Adhesive sheet and method for manufacturing the same, semiconductor device manufacturing method and semiconductor device

ABSTRACT

An adhesive sheet comprising a release substrate  10 , a substrate film  14 , and a first tacky-adhesive layer  12  placed between the release substrate  10  and the substrate film  14 , wherein an annular incision D is formed on the release substrate  10  from the surface of the first tacky-adhesive layer  12  side, the first tacky-adhesive layer  12  is laminated so as to cover the whole inner surface of the incision D in the release substrate  10 , and the incision D has a depth d of less than the thickness of the release substrate  10  and 25 μm or less.

This application is a Divisional application of prior application Ser.No. 11/577,255, filed Feb. 14, 2008, which is a National StageApplication filed under 35 USC 371, of International (PCT) ApplicationNo. PCT/JP2005/018120, filed Sep. 30, 2005. The contents of No.11/577,255 are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to an adhesive sheet and a productionmethod thereof, and a production method of semiconductor device and asemiconductor device.

BACKGROUND ART

Recently, addition of multiple functionalities to and down-sizing ofmobile-related devices have been rapidly required. With this expansion,needs for high-density packaging technologies of semiconductor elementshave been increased each year, in particular, the development of stackedmultichip packaging (hereinafter referred to as “stacked MCP”) in whichsemiconductor elements are laminated takes a central role.

In the development of the stacked MCP technology, two contrary goals,that is, down sizing of the package and multi-layer lamination arecombined. In order to achieve the goals, technologies for making thethickness of silicon wafer used in semiconductor elements thinner haveparticularly been advanced, and wafers having a thickness of 100 μm orless have widely been used and studied. Also, since the multi-layerlamination complicates a package making step, it is demanded to simplifythe package making step and to suggest making processes and materialsthat support the increase of the number of heat histories ofwire-bonding by the multi-layer lamination.

Under the circumstance, as an adhesive material of the stacked MCP,paste materials have been used. The paste materials, however, have someproblems such that run-out of a resin is caused in a bonding process ofsemiconductor elements, or the degree of precision of the film thicknessis low. These problems cause failures in a wire-bonding step or voids ina paste agent, and consequently, when a paste material is used, theabove-mentioned requirement cannot be addressed.

In order to improve the above-mentioned problems, these days, it tendsto use an adhesive in the state of a film instead of a paste material.The adhesives in the state of a film can adjust an amount of a resinrun-out smaller than paste materials, and can make the variation of filmthickness smaller by improving a degree of precision of a filmthickness, and, therefore, the application thereof to the stacked MCP isparticularly widely studied.

The adhesive in the state of a film has usually a structure in which anadhesive layer is formed on a release substrate. One of the typicalmethods for using the adhesive in the state of a film is a method forsticking to a back surface of a wafer. The method for sticking to a backsurface of a wafer is a method in which an adhesive in the state of afilm is directly stuck to a back surface of a silicone wafer used in theproduction of semiconductor element. According to this method, after theadhesive in the state of a film is stuck to the semiconductor wafer, arelease substrate is removed, and then a dicing tape is stuck to theadhesive layer. After that, it is mounted on a wafer ring, and the waferis cut in a desired semiconductor element size together with theadhesive layer. The diced semiconductor elements have the adhesive layerhaving the same size as the element. The semiconductor elements with theadhesive layer are picked-up and stuck to a substrate for mounting theelements in a thermo compression bonding method, or the like.

Dicing tapes used in the method for sticking to a back surface haveusually a structure in which a tacky layer is formed on a substratefilm, and roughly divided into two kinds of the pressure-sensitivedicing tape and the UV type dicing tape. The dicing tapes are requiredto have, as one function, sufficient tack strength so that semiconductorelements are not scattered by a load generated when the wafer is cut ina dicing step. In addition, it is demanded that when the dicedsemiconductor elements are picked-up, the tacking agent is not left oneach element, and therefore, the semiconductor element with the adhesivelayer can be easily picked-up in a die bonder apparatus.

In order to shorten a step for making a package, the requirement offurther process improvement has been increased. According toconventional methods for sticking to a back surface of a wafer, twosteps are necessary, that is, a step in which adhesive in the state of afilm is stuck to a wafer and a subsequent step in which a dicing tape isstuck. In order to simplify this process, adhesive sheet (die bonddicing sheet) having two function of an adhesive in the state of a filmand a dicing tape. As this type of the adhesive sheet, a laminate typehaving a structure in which an adhesive in the state of a film and adicing tape are laminated (see, for example, Patent Documents 1 to 3),and a mono-layered type in which one resin layer has both functions of atacky layer and a adhesive layer (see, for example, Patent Document 4)are proposed.

Also, a method in which such an adhesive sheet is previously processedinto a shape of a wafer constituting a semiconductor element (generallycalled as precut processing) is known (for example, Patent Documents 5and 6). This precut processing is a method in which the resin layer ispunched into a shape matching that of a wafer used, and a part of theresin layer other than the part to which the wafer is stuck is peeledoff.

When such a precut processing is performed, the laminate type adhesivesheet is generally produced by a method in which an adhesive layer in anadhesive in the state of a film is subjected to precut processingmatching with a shape of a wafer, and after it is laminated on a dicingtape, the dicing tape is subjected to precut processing for matchingwith a shape of a wafer ring, or a dicing tape which has previously beensubjected to precut processing into a shape of a wafer ring is laminatedan adhesive in the state of a film which is subjected to precutprocessing.

Also, a mono-layered type adhesive sheet is generally produced by amethod in which a resin layer having two functions of an adhesive layerand a tacky layer (hereinafter referred to as “tacky-adhesive layer”) isformed on a release substrate, the tacky-adhesive layer is subjected toprecut processing, unnecessary parts of the resin layer are removed, andthen it is laminated on a substrate film.

-   [Patent Document 1] Japanese Patent No. 3348923-   [Patent Document 2] Japanese Patent Application Laid-Open    Publication No. 10-335271-   [Patent Document 3] Japanese Patent No. 2678655-   [Patent Document 4] Japanese Patent Application Laid-Open    Publication No. 7-15087-   [Patent Document 5] Japanese Utility Model Application Laid-Open    Publication No. 6-18383-   [Patent Document 6] Japanese Utility Model No. 3021645

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The precut processing of an adhesive film is performed in a method, forexample, shown in FIG. 14. FIG. 14 is a process chart showing series ofsteps for performing a precut processing to a mono-layered adhesivesheet. As shown in FIG. 14, first, a release substrate 10 and apressure-sensitive adhesive film (dicing tape) 20 comprising atacky-adhesive layer 12 and a substrate film 14 are laminated to producean adhesive sheet before precut (FIG. 14 (a)). Next, a cutting operationis performed by inserting a precutting blade C corresponding to adesired shape from a surface F14 of the substrate film 14 until theblade reach a release substrate 10 (FIG. 14 (b)). After that,unnecessary part on the tacky-adhesive layer 12 and the substrate film14 are removed to complete the precut processing (FIG. 14 (c)). In caseof the laminate type adhesive sheet, the same precut processing as inthe above-mentioned procedure is performed except that thetacky-adhesive layer 12 is changed to an adhesive layer and a tackylayer.

Upon the precut processing, if the precutting blade C does not reach therelease substrate 10, the cutting processing is insufficient, and,consequently, a failure in which necessary parts are also peeled off iscaused in a peeling operation of unnecessary parts. In order to avoidsuch a cut failure, the inserting position of the precutting blade C hasconventionally been set at a place deeper than an interface between thetacky-adhesive layer 12 and the release substrate 10.

The present inventors found, however, that the tacky-adhesive layer 12in the adhesive sheet obtained in the precut processing in which theinserting position of the precutting blade C is set deep, as shown inFIG. 15, is bitten by an incision E in the release substrate 10, and aninterface between the release substrate 10 and the tacky-adhesive layer12 is sealed. The present inventors further found that when the adhesivesheet is laminated on a wafer while this state is kept, it is difficultto peel off the tacky-adhesive layer 12 from the release substrate 10,and peel defect easily occurs.

The precut processing of the adhesive film is performed in a method, forexample, shown in FIG. 24. FIG. 24 is a process chart showing series ofsteps for performing a precut processing to a laminated adhesive sheet.As shown in FIG. 24, first, an adhesive in the state of a filmcomprising a release substrate 212 and an adhesive layer 214, and dicingtape comprising a substrate film 224 and a tacky layer 222 are laminatedto produce an adhesive sheet before precut (FIG. 24 (a)). Next, cutoperation in which a precutting blade C corresponding to a desired shapeis inserted form a surface F24 of the substrate film 224 until the bladereaches the release substrate 212 is performed (FIG. 24 (b)). Afterthat, unnecessary parts on the adhesive layer 214, the tacky layer 222and a realest film 224 are removed to complete the precut processing(FIG. 24 (c)). In case of the mono-layered adhesive sheet, the sameprecut processing as in the above-mentioned procedure is performedexcept that, instead of the adhesive layer 214 and the tacky layer 222,a tacky-adhesive layer having the two functions is used. Upon theabove-mentioned precut processing, if the precutting blade C does notreach the release substrate 212, the cutting processing is insufficient,and, consequently, a failure in which necessary parts are also peeledoff is caused in a peeling operation of unnecessary parts. In order toavoid such a cut failure, the inserting position of the precutting bladeC has conventionally been set at a place deeper than an interfacebetween the adhesive layer 214 and the release substrate 212.

The present inventors found, however, that the adhesive layer 214 andthe tacky layer 222 in the adhesive sheet obtained in the precutprocessing in which the inserting position of the precutting blade C isset deep, as shown in FIG. 25, is bitten by an incision F in the releasesubstrate 212, and an interface between the release substrate 212 andthe adhesive layer 214 is sealed. The present inventors further foundthat when the adhesive sheet is laminated on a wafer while this state iskept, it is difficult to peel off the adhesive layer 214 from releasesubstrate 212, and peel defect easily occurs.

In view of the problems in the above-mentioned conventional techniques,the present invention has been made, and the invention aims at providingadhesive sheets which has been subjected to a precut processing, capableof fully inhibiting the peel defect of laminates including atacky-adhesive layer and a substrate film from a release substrate, andthe peel defect of laminates including an adhesive layer, a tacky layerand a substrate film; production methods thereof; method for producing asemiconductor device using the above-mentioned adhesive sheet; andsemiconductor devices.

Means for Solving the Problems

In order to achieve the above-mentioned purposes, the present inventionprovides an adhesive sheet comprising a release substrate, a substratefilm, and a first tacky-adhesive layer placed between the releasesubstrate and the substrate film, wherein an annular incision is formedin the release substrate from the first tacky-adhesive layer side, thefirst tacky-adhesive layer is laminated so as to cover the whole innersurface of the incision in the release substrate, and the incision has adepth of less than the thickness of the release substrate and 25 μm orless.

Here, the incision depth in the present invention refers to a valueobtained by measuring a depth of an incision formed in the releasesubstrate in a thickness direction of the release substrate is measuredwith a cross-section observation using an electron microscope at 10points arbitrarily selected, and averaging the obtained 10 values areaveraged.

The adhesive sheet is an adhesive sheet which has been subjected to theabove-mentioned precut processing. Since, in such an adhesive sheet, thedepth of the incision in the release substrate is within theabove-mentioned range, the first tacky-adhesive layer can besufficiently inhibited from biting to the incision. As a result, theinterface between the release substrate and the first tacky-adhesivelayer is not sealed, and it is easy to peel off the first tacky-adhesivelayer and the substrate film form the release substrate, whereby peeldefect can be sufficiently inhibited.

It is preferable that, in the above-mentioned adhesive sheet, a value of(d/a) satisfies a condition showing the following formula (1):0<(d/a)≦0.7  (1)wherein a (μm) is a thickness of the release substrate, and d (μm) is adepth of the incision.

This gives that the first tacky-adhesive layer can be sufficientlyinhibited from biting to the incision, and the peel defect can besufficiently inhibited.

Also, it is preferable that, in the above-mentioned adhesive sheet, thefirst tacky-adhesive layer has a plane shape which matches a plane shapeof an adherend to which the first tacky-adhesive layer is stuck afterthe release substrate is peeled off.

Examples of the adherend may include, for example, a semiconductorwafer. When the first tacky-adhesive layer has a plane shape whichmatches a plane shape of the semiconductor wafer, it tends to easilyperform a step for dicing the semiconductor wafer. The plane shape ofthe first tacky-adhesive layer does not necessarily match the planeshape of the semiconductor wafer completely, but it may be, for example,analog of the plane shape of the semiconductor wafer or the area thereofmay be a little bigger than that of the semiconductor wafer.

Further, it is preferable that, in the above-mentioned adhesive sheet,the first tacky-adhesive layer has tackiness to the adhered to which thefirst tacky-adhesive layer is stuck and the substrate film at roomtemperature, after peeling off the release substrate.

This gives that the semiconductor wafer is fixed sufficiently when thesemiconductor wafer is subjected to dicing, thus resulting in easydicing. Also, when a wafer ring is used and the adhesive sheet is stuckto the wafer ring so that the first tacky-adhesive layer is closelycontacted to the ring in the dicing of the semiconductor wafer,sufficient tack strength to the wafer ring can be obtained, thusresulting in easy dicing.

Also, it is preferable that the tack strength of the above-mentionedfirst tacky-adhesive layer to the substrate film is lowered byirradiation of a high energy beam.

This gives that the peeling can be easily performed by irradiating highenergy beams such as radial ray when the first tacky-adhesive layer ispeeled off from the substrate film.

Also, it is preferable that the above-mentioned adhesive sheet furthercomprises a second tacky-adhesive layer placed between at least a partof a peripheral part of the first tacky-adhesive layer and the releasesubstrate.

When the adhesive layer comprises such a second tacky-adhesive layer, itis possible to stick this second tacky-adhesive layer to a wafer ring,which is used upon dicing of a semiconductor wafer, and not to directlystick the first tacky-adhesive layer to the wafer ring. When the firsttacky-adhesive layer is stuck directly to the wafer ring, it isnecessary to adjust the tack strength of the first tacky-adhesive layerto a tack strength low enough to peel off from the wafer ring. When thesecond tacky-adhesive layer is stuck to the wafer ring, however, such anadjustment of the tack strength is not required. Consequently, when thefirst tacky-adhesive layer has a sufficiently high tack strength and thesecond tacky-adhesive layer has a tack strength low enough to easilypeel off from the wafer ring, it is possible to more efficiently operatethe dicing step of the semiconductor wafer and the subsequent steps suchas peeling step of the wafer ring. Further, since the tack strength ofthe second tacky-adhesive layer can be controlled sufficiently low, itis easy to generate starting points of peeling between the releasesubstrate and the second tacky-adhesive layer, whereby the secondtacky-adhesive layer, the first tacky-adhesive layer and the substratefilm can be easily peeled off from the release substrate, and thus thepeel defect can be sufficiently inhibited.

Here, it is preferable that the above-mentioned second tacky-adhesivelayer has tackiness to an adherend to which the second tacky-adhesivelayer is stuck and the first tacky-adhesive layer at room temperature,after the release substrate is peeled off.

Also, it is preferable that the above-mentioned adhesive sheet furthercomprises an intermediate layer placed between at least a part of theperipheral part of the first tacky-adhesive layer and the secondtacky-adhesive layer.

When the sheet comprises such an intermediate layer, it is possible toraise a degree of freedom of choice of materials for the secondtacky-adhesive layer. For example, when a second tacky-adhesive layerhaving an adhesive sheet is produced, it is necessary to precut a secondtacky-adhesive layer after the second tacky-adhesive layer is laminatedon the release substrate. An inexpensive tacky-adhesive layer does nothave self-supporting property, and therefore it can be difficult tocompletely peeled off it from the release substrate. However, when theintermediate layer is formed on the second tacky-adhesive layer, it ispossible to easily remove the second tacky-adhesive layer together withthe intermediate layer on precut, whereby the efficiency of the workingcan be promoted as well as the degree of freedom of the choice of thematerial for the second tacky-adhesive layer can be raised. This givethat it is possible to easily adjust the tack strength of the secondtacky-adhesive layer, it is easy to generate starting points of peelingbetween the release substrate and the second tacky-adhesive layer, andthe second tacky-adhesive layer, the first tacky-adhesive layer, and thesubstrate film are easily peeled off from the release substrate, as aresult, the peel defect can be sufficiently inhibited.

The present invention provides a method for producing an adhesive sheetincluding a release substrate, a substrate film and a firsttacky-adhesive layer placed between the release substrate and thesubstrate film, comprising: a first laminating step in which the firsttacky-adhesive layer and the substrate film are laminated on the releasesubstrate; and a first cutting step in which an incision is made from anopposite side of the first tacky-adhesive layer on the substrate filmuntil it reaches the release substrate, after the first laminating step,to form an annular incision in the release substrate, wherein theincision is made in the first cuffing step so as to have a depth of lessthan the thickness of the release substrate and 25 μm or less.

Also the present invention provides a method for producing an adhesivesheet including a release substrate, a substrate film, a firsttacky-adhesive layer placed between the release substrate and thesubstrate film, and a second tacky-adhesive layer placed between therelease substrate and the first tacky-adhesive layer, comprising: asecond laminating step in which the second tacky-adhesive layer ispartly laminated on the release substrate; a third laminating step inwhich the first tacky-adhesive layer and the substrate film arelaminated on the release substrate and the second tacky-adhesive layer;and a second cutting step in which an incision is made from an oppositeside of the first tacky-adhesive layer on the substrate film until itreaches the release substrate to form an annular incision in the releasesubstrate, wherein the cutting in the second cutting step is performedso that the second tacky-adhesive layer is placed between at least apart of the peripheral part of the first tacky-adhesive layer and therelease substrate within the area of the inside of the incision, and theincision has a depth of less than the thickness of the release substrateand 25 μm or less.

Further, the present invention provides a method for producing anadhesive sheet including a release substrate, a substrate film, a firsttacky-adhesive layer placed between the release substrate and thesubstrate film, a second tacky-adhesive layer placed between the releasesubstrate and the first tacky-adhesive layer, and an intermediate layerplaced between the first tacky-adhesive layer and the secondtacky-adhesive layer, comprising: a forth laminating step in which thesecond tacky-adhesive layer and the intermediate layer are partlylaminated on the release substrate; a fifth laminating step in which thefirst tacky-adhesive layer and the substrate film are laminated on therelease substrate and the intermediate layer; and a third cutting stepin which an incision is made from an opposite side of the firsttacky-adhesive layer on the substrate film until it reaches the releasesubstrate to form an annular incision in the release substrate, whereinthe cutting in the third cutting step is performed so that the secondtacky-adhesive layer and the intermediate layer are placed between atleast a part of the peripheral part of the first tacky-adhesive layerand the release substrate within the area of the inside of the incision,and the incision has a depth of less than the thickness of the releasesubstrate and 25 μm or less.

In these methods for producing an adhesive sheet, precut processing isperformed and a depth of an incision formed on the release substrate bythe precut processing is adjusted to the above-mentioned range. Thisgives that peel defect can be sufficiently inhibited on the obtainedadhesive sheet.

Also, it is preferable that the incision is made so that a value of(d/a) satisfies the following formula (1):0<(d/a)≦0.7  (1)wherein a (μm) is a thickness of the release substrate, and d (μm) is adepth of the incision in the first to the third cutting steps.

This gives that an adhesive sheet capable of more sufficientlyinhibiting peel defect can be obtained.

The present invention provides a method for producing a semiconductordevice comprising: a first peeling-off step in which the releasesubstrate is peeled off from the adhesive sheet defined in any one ofclaims 1 to 5 to give a first laminate including the substrate film andthe first tacky-adhesive layer; a sticking step in which the firsttacky-adhesive layer in the first laminate is stuck to a semiconductorwafer; a first dicing step in which the semiconductor wafer and thefirst tacky-adhesive layer are subjected to dicing to give asemiconductor element to which the first tacky-adhesive layer is stuck;a first picking-up step in which the semiconductor element to which thefirst tacky-adhesive layer adheres is picked up from the substrate film;and a first bonding step in which the semiconductor element is bondedthrough the first tacky-adhesive layer to a support member for mountinga semiconductor element.

Also, the present invention provides a method for producing asemiconductor device comprising: a second peeling-off step in which therelease substrate is peeled off from the adhesive sheet of the presentinvention to give a second laminate including the substrate film, thefirst tacky-adhesive layer and the second tacky-adhesive layer; a secondsticking step in which the first tacky-adhesive layer in the secondlaminate is stuck to a semiconductor wafer, and the secondtacky-adhesive layer is stuck to a wafer ring; a second dicing step inwhich the semiconductor wafer and the first tacky-adhesive layer aresubjected to dicing to give a semiconductor element to which the firsttacky-adhesive layer adheres; a second picking-up step in which thesemiconductor element to which the first tacky-adhesive layer adheres ispicked-up from the substrate film; and a second bonding step in whichthe semiconductor element is bonded through the first tacky-adhesivelayer to a support member for mounting a semiconductor element.

Further, the present invention provides a method for producing asemiconductor device comprising: a third peeling-off step in which therelease substrate is peeled off from the adhesive sheet of the presentinvention to give a third laminate including the substrate film, thefirst tacky-adhesive layer, the intermediate layer, and the secondtacky-adhesive layer; a third sticking step in which the firsttacky-adhesive layer in the third laminate is stuck to a semiconductorwafer, and the second tacky-adhesive layer is stuck to a wafer ring; athird dicing step in which the semiconductor wafer and the firsttacky-adhesive layer are subjected to dicing to give a semiconductorelement to which the first tacky-adhesive layer adheres; a thirdpicking-up step in which the semiconductor element to which the firsttacky-adhesive layer adheres is picked-up from the substrate film; and athird bonding step in which the semiconductor element is bonded throughthe first tacky-adhesive layer to a support member for mounting asemiconductor element.

According to these production methods, since the adhesive sheet of thepresent invention is used in the production step, peel defect causedduring the production steps can be sufficiently inhibited andsemiconductor devices can be efficiently and surely produced.

The present invention further provides a semiconductor device producedaccording to the method for producing a semiconductor device of thepresent invention.

The present invention provides an adhesive sheet comprising a releasesubstrate, an adhesive layer, a tacky layer, and a substrate film, whichare laminated in order, wherein the adhesive layer has a pre-determinedfirst plane shape and is partly formed on the release substrate, a firstincision is formed from a side bringing contact with the adhesive layeralong the periphery of the plane shape on the release substrate; and thefirst incision has a depth of less than the thickness of the releasesubstrate and 25 μm or less.

Here, the incision depth in the present invention refers to a valueobtained by measuring a depth of an incision formed in the releasesubstrate in a thickness direction of the release substrate is measuredwith a cross-section observation using an electron microscope at 10points arbitrarily selected, and averaging the obtained 10 values areaveraged.

The adhesive sheet is an adhesive sheet which has been subjected to theabove-mentioned precut processing. Since, in such an adhesive sheet, thedepth of the first incision in the release substrate is within theabove-mentioned range, the adhesive layer and the tacky layer can besufficiently inhibited from biting to the first incision. As a result,the interface between the release substrate and the adhesive layer isnot sealed, and it is easy to peel off the adhesive layer, the tackylayer, and the substrate film form the release substrate, whereby peeldefect can be sufficiently inhibited.

Also, it is preferable that, in the above-mentioned adhesive sheet, avalue of (d1/a) satisfies the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate, and d1 (μm) is adepth of the first incision.

This gives that the adhesive layer and the tacky layer can besufficiently inhibited from biting to the first incision, and the peeldefect can be sufficiently inhibited.

It is preferable that, in the above-mentioned adhesive sheet, the tackylayer covers the adhesive layer and is laminated so as to bring contactwith the release substrate around the adhesive layer. It is preferablethat, in the above-mentioned adhesive sheet having the tacky layer, thetacky layer and the substrate film have pre-determined second planeshapes and are partly formed on the release substrate, a second incisionis formed from a side bringing contact with the tacky layer along theperiphery of the second plane shape on the release substrate; and thesecond incision has a depth of less than the thickness of the releasesubstrate and 25 μm or less.

In such adhesive sheets, the adhesive layer is subjected to the precutprocessing, and the tacky layer, which is laminated so as to cover thisadhesive layer, and the substrate film are separately subjected to theprecut processing. Since the depth of the second incision in the releasesubstrate of the adhesive sheet is within the above-mentioned range, thetacky layer can be sufficiently inhibited from the biting to the secondincision. As a result, the interface between the release substrate andthe tacky layer is not sealed, and the tacky layer and the substratefilm are easily peeled off from the release substrate, thus resulting insufficient inhibition of the peel defect.

It is preferable that, in the above-mentioned adhesive sheet, a value of(d2/a) satisfies the following formula (3):0<(d2/a)≦0.7  (3)wherein a (μm) is a thickness of the release substrate, and d2 (μm) is adepth of the second incision.

This gives that the tacky layer can be sufficiently inhibited from thebiting to the second incision, and the peel defect can be sufficientlyinhibited.

Also it is preferable that, in the above-mentioned adhesive sheet, theadhesive layer has a plane shape which matches a plane shape of anadherend to which the first tacky layer is stuck after the releasesubstrate is peeled off.

Examples of the adherend may include, for example, a semiconductorwafer. When the adhesive layer has a plane shape which matches a planeshape of the semiconductor wafer, it tends to easily perform a step fordicing the semiconductor wafer. The plane shape of the adhesive layerdoes not necessarily match the plane shape of the semiconductor wafercompletely, but it may be, for example, analog of the plane shape of thesemiconductor wafer or the area thereof may be a little bigger than thatof the semiconductor wafer.

Further, it is preferable that, in the above-mentioned adhesive sheet,the tacky layer has tack strength to the adherend to which the tackylayer is stuck and the adhesive layer at room temperature after therelease substrate is peeled off.

This gives that the semiconductor wafer is fixed sufficiently when thesemiconductor wafer is subjected to dicing, thus resulting in easydicing. Also, when a wafer ring is used and the adhesive sheet is stuckto the wafer ring so that the tacky layer is closely contacted to thering in the dicing of the semiconductor wafer, sufficient tack strengthto the wafer ring can be obtained, thus resulting in easy dicing.

Also, it is preferable that, in the above-mentioned tacky layer, thetacky layer has tack strength to the adhesive layer, which is lowered byirradiating high energy beams.

This gives that the peeling can be easily performed by irradiating highenergy beams such as radial ray when adhesive layer and the tacky layerare peeled off from each other.

The present invention also provide a method for producing an adhesivesheet including a release substrate, an adhesive layer, a tacky layerand a substrate film, which are laminated in order, comprising a firstlaminating step in which the adhesive layer, the tacky layer, and thesubstrate film are laminated in order on the release substrate; and afirst cutting step in which an incision is made from an opposite sidebringing contact with the tacky layer on the substrate film until itreaches the release substrate to cut the adhesive layer, the tacky layerand the substrate film in pre-determined plane shapes and to form afirst incision in the release substrate; wherein the incision is made sothat the first incision has a depth of less than the thickness of therelease substrate and 25 μm or less in the first cutting step.

In the method for producing an adhesive sheet, precut processing isperformed and a depth of a first incision formed on the releasesubstrate by the precut processing is adjusted to the above-mentionedrange. This gives that peel defect can be sufficiently inhibited on theobtained adhesive sheet.

Also it is preferable that the incision is made so that a value of(d1/a) satisfies the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate, and d1 (μm) is adepth of the first incision in the first cutting step.

This gives that an adhesive sheet capable of more sufficientlyinhibiting peel defect can be obtained.

The present invention further provides a method for producing anadhesive sheet including a release substrate, an adhesive layer, a tackylayer, and substrate film, which are laminated in order, comprising: asecond laminating step in which the adhesive layer is laminated on therelease substrate; a second cutting step in which an incision is madefrom an opposite side bringing contact with the release substrate on theadhesive layer until it reaches the release substrate to cut theadhesive layer in a pre-determined plane shape and to form a firstincision in the release substrate; and a third laminating step in whichthe tacky layer, and the substrate film are laminated in order on theadhesive layer, wherein the incision is made so that the first incisionhas a depth of less than the thickness of the release substrate and 25μm or less in the second cutting step.

In this method for producing an adhesive sheet, precut processing isalso performed and a depth of a first incision formed on the releasesubstrate by the precut processing is also adjusted to theabove-mentioned range, and accordingly, the peel defect can besufficiently inhibited on the obtained adhesive sheet.

It is preferable that the incision is made so that a value of (d1/a)satisfies the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate, and d1 (μm) is adepth of the first incision in the second cutting step.

This gives that an adhesive sheet capable of more sufficientlyinhibiting the peel defect can be obtained.

Also, it is preferable that, in the above-mentioned method for producingthe adhesive sheet, the tacky layer covers the adhesive layer, and thetacky layer and the substrate film are laminated so as to bring contactwith the release substrate around the adhesive layer in the thirdlaminating step; which further comprises a third cutting step in whichan incision is made from an opposite side bringing contact with thetacky layer on the substrate film until it reaches the release substrateto cut the substrate film and the tacky layer in a pre-determined planeshapes and to form a second incision in the release substrate, thesecond incision in the third cutting step being made so as to have adepth less than the thickness of the release substrate and 25 μm orless.

In the production method of the adhesive sheet, the depth of the secondincision formed on the release substrate by the precut processing isadjusted to the above-mentioned range, and accordingly the obtainedadhesive sheet can sufficient inhibited the peel defect.

It is preferable that the incision is made so that a value of (d2/a)satisfies the following formula (3):0<(d2/a)≦0.7  (3)wherein a (μm) is a thickness of the release substrate, and d2 (μm) is adepth of the second incision in the third cutting step.

This gives that an adhesive sheet capable of more sufficientlyinhibiting the peel defect can be obtained.

The present invention also provides a method for producing asemiconductor device comprising: a sticking step in which a laminateincluding the adhesive layer, the tacky layer and the substrate film inthe adhesive sheet of the present invention, is peeled out from therelease substrate, and the laminate is stuck through the adhesive layerto a semiconductor wafer to give a semiconductor wafer having thelaminate; a dicing step in which the semiconductor wafer having thelaminate is subjected to dicing to give a semiconductor element having alaminate with a pre-determined size; a peeling-off step in which thetacky layer on the laminate is irradiated with high energy beams tolower the tack strength of the tacky layer to the adhesive layer, andthen the tacky layer and the substrate film are peeled off form theadhesive layer to give a semiconductor element having the adhesivelayer; and a bonding step in which the semiconductor element having theadhesive layer is bonded through the adhesive layer to a support memberfor mounting a semiconductor element.

According to the production method, since the adhesive sheet of thepresent invention is used in the production step, peel defect causedduring the production steps can be sufficiently inhibited andsemiconductor devices can be efficiently and surely produced.

Further, the present invention provides a semiconductor device which isproduced according to the method for producing a semiconductor device ofthe present invention.

Effects of the Invention

According to the present invention, adhesive sheets to which the precutprocessing is subjected and which is capable of sufficiently inhibitingthe peel defect of the laminate including the tacky-adhesive layer andthe substrate film or the peel defect of the laminate including theadhesive layer, tacky layer and the substrate film, from the releasesubstrate; production methods thereof, methods for producing asemiconductor device using the adhesive sheet, and semiconductor devicescan be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plane view showing a first embodiment of an adhesive sheetof the present invention.

FIG. 2 is a schematic cross-section view of the adhesive sheet 1 shownin FIG. 1 which is cut along the line A1-A1 in FIG. 1.

FIG. 3 is a schematic cross-section view showing a state in which afirst laminate 20, a semiconductor wafer 32 and a wafer ring 34 arestuck in an adhesive sheet.

FIG. 4 is a plane view showing a second embodiment of an adhesive sheetof the present invention.

FIG. 5 is a schematic cross-section view of the adhesive sheet 2 shownin FIG. 4 which is cut along the line A2-A2 in FIG. 4.

FIG. 6 is a plane view showing a third embodiment of an adhesive sheetof the present invention.

FIG. 7 is a schematic cross-section view of the adhesive sheet 3 shownin FIG. 6 which is cut along the line A3-A3 in FIG. 6.

FIG. 8 is a process chart showing series of production steps of theadhesive sheet 1.

FIG. 9 is a process chart showing series of production steps of theadhesive sheet 2.

FIG. 10 is a process chart showing series of production steps of theadhesive sheet 3.

FIG. 11 is a process chart showing series of steps for sticking a secondlaminate 20 to a semiconductor wafer 32.

FIG. 12 is a process chart showing series of steps for dicing thesemiconductor wafer 32.

FIG. 13 is schematic cross-section view showing one embodiment of asemiconductor element of the present invention.

FIG. 14 is a process chart showing series of steps for performing aprecut processing to a mono-layered adhesive sheet.

FIG. 15 is an enlarged schematic cross-section view of the vicinity ofan incision E formed on a release substrate 10 according to theconventional precut processing.

FIG. 16 is a plane view showing a seventh embodiment of an adhesivesheet of the present invention.

FIG. 17 is a schematic cross-section view of the adhesive sheet 201shown in FIG. 16 which is cut along the line A11-A11 in FIG. 16.

FIG. 18 is a plane view showing an eighth embodiment of an adhesivesheet of the present invention.

FIG. 19 is a schematic cross-section view of the adhesive sheet 202shown in FIG. 18 which is cut along the line A12-A12 in FIG. 18.

FIG. 20 is a plane view showing a ninth embodiment of an adhesive sheetof the present invention.

FIG. 21 is schematic cross-section view of the adhesive sheet 203 shownin FIG. 20 which is cut along the line A13-A13 in FIG. 20.

FIG. 22 is a process chart showing series of steps for sticking alaminate 210 to a semiconductor wafer 32.

FIG. 23 is a schematic cross-section view showing one embodiment of asemiconductor element of the present invention.

FIG. 24 is a process chart showing series of steps for performing aprecut processing to a laminated adhesive sheet.

FIG. 25 is an enlarged schematic cross-section view of the vicinity ofan incision F formed on a release substrate 212 according to theconventional precut processing.

DESCRIPTION OF THE REFERENCE SYMBOLS

1, 2, 3, 201, 202 and 203: adhesive sheets, 10 and 212: releasesubstrates, 12: a first tacky-adhesive layer, 14 and 224: substratefilms, 16: a second tacky-adhesive layer, 18: an intermediate layer, 20:a first laminate, 22: a second laminate, 24: a third laminate, 32:semiconductor wafer, 33 and 72: semiconductor elements, 34: wafer ring,36: stage, 42 and 242: first rolls, 44: a core, 52 and 252: secondrolls, 54: a core, 62 and 68: rolls, 70: organic substrate, 71: asupporting member for mounting a semiconductor, 74: a circuit pattern,76: a terminal, 78: a wire stick, 80: a sealer, 210: a laminate, 214: anadhesive layer, 220: a pressure-sensitive adhesive film, and 222: tackylayer.

BEST MODES FOR CARRYING OUT THE INVENTION

Now, the most preferable embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. In thefollowing description, the same numbers are given to the same orcorresponding structure members, and when the explanations thereofoverlap, the later explanations are omitted. The position relations suchas top and bottom, or right and left are based on a position relationindicated in a drawing, unless otherwise noted. In addition, sizeproportions are not limited to those shown in drawings.

Adhesive Sheet First Embodiment

FIG. 1 is a plane view showing a first embodiment of an adhesive sheetof the present invention; and FIG. 2 is a schematic cross-section viewof the adhesive sheet 1 shown in FIG. 1 which is cut along the lineA1-A1 in FIG. 1. As shown in FIG. 1 and FIG. 2, adhesive sheet 1 has astructure in which a release substrate 10, a first tacky-adhesive layer12 and a substrate film 14 are laminated in order. A first laminate 20composed of the first tacky-adhesive layer 12 and the substrate film 14is cut in a pre-determined plane shape, and partly laminated on therelease substrate 10. Further, in the release substrate 10, an annularincision D is formed along a periphery of the plane shape of the firstlaminate 20 from a surface facing the first tacky-adhesive layer 12 in athickness direction of the release substrate 10. The first laminate 20is laminated so as to cover the whole inside surface of the incision Dformed in the release substrate 10.

Here, the above-mentioned pre-determined plane shape of the firstlaminate 20 is not particularly limited so long as it the first laminate20 can be partly laminated on the release substrate 10. It is preferablethat the above-mentioned pre-determined plane shape of the firstlaminate 20 matches a plane shape of an adherend such as a semiconductorwafer, and a shape that can be easily stuck to a semiconductor waferhaving a shape of, for example, a circle, a rough circle, a quadrangle,a pentagon, a hexagon, an octagon or a wafer shape (a shape having astraight line in a part of the circumference of the circle) ispreferable. Of these, the circle and the wafer shape are preferable, inorder to reduce wasted part such as parts other that a part for mountingthe semiconductor wafer.

When the semiconductor wafer is subjected to dicing, a wafer ring isusually used for treating it on a dicing apparatus. In such a case, asshown in FIG. 3, the release substrate 10 is peeled off from an adhesivesheet 1, a wafer ring 34 is stuck to the first tacky-adhesive layer 12,and a semiconductor wafer 32 is stuck to the inside thereof. Here, thewafer ring 34 has a circular cylinder frame or a square pole frame. Itis further preferable that a first laminate 20 of the adhesive sheet 1has a plane shape matching the shape of the wafer ring 34.

Also, it is preferable that the first tacky-adhesive layer 12 cansufficiently hold the adherends such as the semiconductor wafer and thewafer ring at room temperature (25° C.), and the thickness thereof isthick enough to be able to peel off the wafer ring, and the like afterdicing.

In the adhesive sheet 1, the incision D formed in the release substrate10 has an incision depth d less than the thickness of the releasesubstrate 10 and 25 μm or less.

Now, each layer constituting the adhesive sheet 1 will be described indetail.

The release substrate 10 serves as a carry film when the adhesive sheet1 is used. As the release substrate 10, for example, polyester filmssuch as polyethylene terephthalate film; polyolefin firms such aspolytetrafluoroethylene film, polyethylene film, polypropylene film,polymethylpentene film, and polyvinyl acetate film; plastic films suchas polyvinyl chloride film and polyimide film, and the like can be used.In addition, paper sheets, non-woven fabrics, metal foils, and the likecan also be used.

Also, it is preferable that the surface of the release substrate 10facing the first tacky-adhesive layer 12 is surface-treated with arelease agent such as a silicone releasing agent, fluorine releasingagent, long chain alkyl acrylate releasing agent.

The thickness of the release substrate 10 can suitably selected within arange where workability is not impaired upon use. The release substrate10 has a thickness of, preferably, 10 to 500 μm, more preferably 25 to100 μm, particularly preferably 30 to 50 μm.

The first tacky-adhesive layer 12 may include, for example, athermoplastic component, a heat-polymerizable component, a radialray-polymerizable component, and the like. When such a component isincluded in the composition, the first tacky-adhesive layer 12 can havea curable property with radial rays (such as ultraviolet radiation) orheat. Also, a component which is cured with high energy beams other thanthe radial rays (such as an electron beam, and the like) may beincluded.

Here, when the radial ray-polymerizable component is included in thefirst tacky-adhesive layer 12, pick-up can be easily performed byimproving tack strength upon dicing with optical illumination after thefirst tacky-adhesive layer 12 is stuck to the adherend to thesemiconductor wafer and before performing the dicing, or conversely bylowering the tack strength with optical illumination after the dicing isperformed. In the present invention, as such a radial ray-polymerizablecomponent, any compound which is used in conventional radialray-polymerizable dicing sheets can be used without particularlimitations. Also, when a thermosetting compound is included, thereliability of the semiconductor device can be improved by curing thefirst tacky-adhesive layer 12 with heat generated when the semiconductorelement is mounted on a support member on which the element is mounted,or it passes through a solder reflow. Now, each component will bedescribed in detail.

As the thermoplastic component used in the first tacky-adhesive layer12, resins having thermal plasticity, and resins having thermalplasticity at least in its uncured state and forming a cross-linkedstructure after heating can be used without particular limitations. Assuch a thermoplastic component, for example, (1) components having a Tg(glass transition temperature) of 10 to 100° C. and a weight averagemolecular weight of 5000 to 200000, and (2) components having a Tg of−50 to 10° C. and a weight average molecular weight of 100000 to 1000000are preferably used.

Examples of the above-mentioned thermoplastic resin (1) may include, forexample, polyimide resins, polyamide resins, polyether imide resins,polyamide imide resins, polyester resins, polyester imide resins,phenoxy resins, polysulfone resins, polyether sulfone resins,polyphenylene sulfide resins, polyether ketone resins, and the like. Ofthese, it is preferable to use the polyimide resins. As theabove-mentioned thermoplastic resin (2), it is preferable to usepolymers having a functional monomer.

Preferable one of these thermoplastic resins is the polyimide resin.Such a polyimide resin may be obtained by, for example, condensationreaction of tetracarboxylic dianhydride and diamine in a known manner.That is, addition reaction of tetracarboxylic dianhydride and diamine isperformed in equal mole or almost equal mole (the addition order of eachcomponent is arbitrary) in an organic solvent at a reaction temperatureof 80° C. or less, preferably 0 to 60° C. The viscosity of the reactionliquid gradually increases with the advance of the reaction, and then apolyamide acid, which is a precursor of polyimide, is generated.

Preferable one of these thermoplastic resins is the polymer including afunctional monomer. Examples of the functional group in such a polymermay include, for example, glycidyl group, acryloyl group, methacryloylgroup, hydroxyl group, carboxyl group, isocyanurate group, amino group,amido group, and the like. Of these, glycidyl group is preferable. Morespecifically, glycidyl group-containing (meth)acrylic copolymers, whichinclude a functional monomer such as glycidyl acrylate or glycidylmethacrylate, are preferable, and the copolymers which arenon-compatible with a thermosetting resin such as an epoxy resin aremore preferable.

Examples of the high molecular weight component having a weight averagemolecular weight of 100000 or more among the above-mentioned polymerhaving a functional monomer may include glycidyl group-containing(meth)acrylic copolymers having a functional monomer such as glycidylacrylate or glycidyl methacrylate, and a weight average molecular weightof 100000 or more, and the like. Of these, the copolymers non-compatiblewith epoxy resins are preferable.

As the above-mentioned glycidyl group-containing (meth)acryliccopolymer, for example, (meth)acrylic ester copolymers, acrylic rubbers,and the like may be used, and the acrylic rubbers are more preferable.The acrylic rubber includes an acrylic ester as a main component, and ismainly composed of a copolymer comprising butyl acrylate andacrylonitrile, or a copolymer comprising ethyl acrylate andacrylonitrile.

The above-mentioned functional monomer refers to a monomer having afunctional group, as such a monomer it is preferable to use glycidylacrylate, glycidyl methacrylate or the like. The glycidylgroup-containing (meth)acrylic copolymer having a weight averagemolecular weight of 100000 or more is specifically, for example,HTR-860P-3™ manufactured by Nagase Chemtex Corporation, and the like.

An amount of the epoxy resin-containing monomer units such as glycidylacrylate or glycidyl methacrylate as mentioned above is preferably 0.5to 50% by weight based on the whole weight of the monomers, foreffectively forming a network structure by curing with heat. The amountis preferably from 0.5 to 6.0% by weight, more preferably 0.5 to 5.0% byweight, particularly preferably 0.8 to 5.0% by weight, from the viewpoint that adhesive strength can be secured as well as gelation can beprevented.

Examples of the above-mentioned functional monomer other than theglycidyl acrylate and the glycidyl methacrylate may include, forexample, ethyl(meth)acrylate, butyl(meth)acrylate, and the like. Theymay be used alone or as a combination thereof. In the present invention,the ethyl(meth)acrylate refers to ethyl acrylate, or ethyl methacrylate.The mix ratio of the functional monomers in the combination thereof isdecided in consideration of the Tg of the glycidyl group-containing(meth)acrylic copolymer, and it is preferable that the ratio is set sothat the Tg is −10° C. or more. When the Tg is −10° C. or more, tuckproperty of a tacky-adhesive layer is appropriate in B stage, andhandling tends to be good.

When the high molecular weight component having the functional monomerand a weight average molecular weight of 100000 or more is produced bypolymeriaing the above-mentioned monomer,

the polymerization method is not particularly limited, and, for example,methods such as pearl polymerization or solution polymerization may beused.

Although the high molecular weight component having a functional monomerhas a weight average molecular weight of 100000 or more, the molecularweight is preferably from 300000 to 3000000, more preferably from 500000to 2000000. When the weight average molecular weight is within thisrange, the strength, flexibility and tuck property of the sheet or filmthereof are appropriate, and the flow property is appropriate, and,consequently, it tends to provide good circuit self-compacting propertyof wiring. In the present invention, the weight average molecular weightis a value obtained by performing a measurement with gel permeationchromatography and converting the measured value using a standardpolystyrene analytical curve.

The high molecular weight component having a functional monomer and aweight average molecular weight of 100000 or more is used in an amountof, preferably, 10 to 400 parts by weight based on 100 parts by weightof heat-polymerizable component. When the amount is within this range,the storage elasticity modulus and the inhibition of flow property uponmolding can be secured, and the handling can tend to be good at a hightemperature. Also, the high molecular weight component is used in anamount of, more preferably 15 to 350 parts by weight, particularlypreferably 20 to 300 parts by weight based on 100 parts by weight of theheat-polymerizable component.

As heat-polymerizable component used in the first tacky-adhesive layer12, any compounds may be used without particular limitations so long asthey polymerize with heat, and examples thereof may include compoundshaving a functional group such as glycidyl group, acryloyl group,methacryloyl group, hydroxyl group, carboxyl group, isocyanurate group,amino group, or amido group. They may be used alone or in combinationthereof. It is preferable to use thermosetting resins which are curedwith heat to exert adhesive action, in consideration of the heatresistance as an adhesive sheet.

Examples of the thermosetting resin may include, for example, epoxyresins, acrylic resins, silicone resins, phenol resins, thermosettingpolyimide resins, polyurethane resins, melamine resins, urea resins, andthe like. In particular, the epoxy resins are preferable, becauseadhesive sheets having high heat resistance, workability, andreliability can be obtained therefrom.

The epoxy resins are not particularly limited so long as they cure toshow adhesive action. As such an epoxy resin, for example, difunctionalepoxy resins such as a bisphenol A type epoxy resin, and novolac typeepoxy resins such as a phenol-novolac type epoxy resin or a cresolnovolac type epoxy resin may be used. In addition, generally knownresins such as a polyfunctional epoxy resin, a glycidyl amine type epoxyresin, a hetero ring-containing epoxy resin, and an alicyclic epoxyresin may be used.

Examples of the bisphenol A type epoxy resin may include Epikote seriesmanufactured by Japan Epoxy Resins Co., Ltd. (Epikote 807, Epikote 815,Epikote 825, Epikote 827, Epikote 828, Epikote 834, Epikote 1001,Epikote 1004, Epikote 1007, and Epikote 1009); DER-330, DER-301 andDER-361 manufactured by Dow Chemical Company; YD 8125 and YDF 8170manufactured by Tohto Kasei Co., Ltd., and the like.

Examples of the phenol-novolac type epoxy resin may include Epikote 152and Epikote 154 manufactured by Japan Epoxy Resins Co., Ltd.; EPPN-201manufactured by Nippon Kayaku Co., Ltd.; DEN-438 manufactured by DowChemical Company, and the like. Examples of the o-cresol novolac typeepoxy resin may include EOCN-102 S, EOCN-103 S, EOCN-104 S, EOCN-1012,EOCN-1025, and EOCN-1027 manufactured by Nippon Kayaku Co., Ltd.; YDCN701, YDCN 702, YDCN 703, and YDCN 704 manufactured by Tohto Kasei Co.,Ltd., and the like.

Examples of the polyfunctional epoxy resin may include Epon 1031 Smanufactured by Japan Epoxy Resins Co., Ltd.; Araldit 0163 manufacturedby Chiba Speciality Chemicals Inc.; Denakole EX-611, EX-614, EX-614B,EX-622, EX-512, EX-521, EX-421, EX-411, EX-321 manufactured by NagaseChemtex Corporation, and the like.

Examples of the amine type epoxy resin may include Epikote 604manufactured by Japan Epoxy Resins Co., Ltd.; YH-434 manufactured byTohto Kasei Co., Ltd.; TETRAD-X and TETRAD-C manufactured by MitsubishiGas Chemical Company, Inc.; ELM-120 manufactured by Sumitomo ChemicalCo., Ltd., and the like.

Examples of the hetero ring-containing epoxy resin may include AralditPT 810 manufactured by Chiba Speciality Chemicals Inc.; ERL 4234, ERL4299, ERL 4221, and ERL 4206 manufactured by UCC INC., and the like.These epoxy resins may be used alone or in combination thereof.

When the epoxy resin is used, it is preferable to use a curing agent forepoxy resin. Known curing agents which are usually used may be used asthe curing agent for epoxy resin. Examples thereof are, for example,amines, polyamide, acid anhydride, polysulfide, boron trifluoride,dicyandiamide, bisphenols having two or more phenolic hydroxyl group inone molecule such as bisphenol A, bisphenol F and bisphenol S, phenolresins such as phenol-novolac resin, bisphenol A-novolac resin andcreosol-novolac resin, and the like. The phenol resins such as thephenol-novolac resin, the bisphenol A-novolac resin and thecreosol-novolac resin are particularly preferable, because they havegood electric corrosion resistance when they absorb moisture. In thepresent invention, the curing agent for epoxy resin includes curingaccelerators which catalytically affect the epoxy group and acceleratesformation of cross-linking.

Preferable examples of the above-mentioned phenol resin curing agent mayinclude, for example, Phenolite™ LF 2882, Phenolite LF 2822, PhenoliteTD-2090, Phenolite TD-2149, Phenolite VH-4150, and Phenolite VH4170manufactured by Dainippon Ink and Chemicals, Incorporated; H-1™manufactured by Meiwa Plastic Industries, Ltd.; E-Picure™ MP 402 FPY,E-picure YL 6065, and E-picure YLH 129 B65 manufactured by Japan EpoxyResins Co., Ltd.; Milex™ XL, Milex XLC, Milex RN, Milex RS, and Milex VRmanufactured by Mitsui Chemicals, Inc., and the like.

The radial ray-polymerizable components used in the first tacky-adhesivelayer 12 are not particularly limited, and the following compounds maybe used, for example, methyl acrylate, methyl methacrylate, ethylacrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, pentenyl acrylate,tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, diethyleneglycol diacrylate, triethylene glycol diacrylate, tetraethylene glycoldiacrylate, diethylene glycol dimethacrylate, triethylene glycoldimethacrylate, tetraethylene glycol dimethacrylate, trimethylol propanediacrylate, trimethylol propane triacrylate, trimethylol propanedimethacrylate, trimethylol propane trimethacrylate, 1,4-butanedioldiacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate,1,6-hexanediol dimethacrylate, pentaerythritol triacrylate,pentaerythritol tetraacrylate, pentaerythritol trimethacrylate,pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate,dipentaerythritol hexamethacrylate, styrene, divinyl benzene, 4-vinyltoluene, 4-vinyl pyridine, N-vinylpyrrolidone, 2-hydroxyethyl acrylate,2-hydroxyethyl methacrylate, 1,3-acryloyloxy-2-hydroxypropane,1,2-methacryloyloxy-2-hydroxypropane, methylene bisacrylamide,N,N-dimethylacrylamide, N-methylolacrylamide, triacrylate oftris(β-hydroxyethyl)isocyanurate, and the like.

Also, to the first adhesive layer 12 may be added a photoinitiator (suchas a compound forming free radical with irradiation of actinic light.

Examples of the photoinitiator may include, for example, aromaticketones such as benzophenone, N,N′-tetramethyl-4,4′-diaminobenzophenone(Michler's ketone), N,N′-tetraethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylaminobenzophenone,2-benzyl-2-dimethylaminol-(4-morpholinophenyl)-butanone-1,2,2-dimethoxy-1,2-diphenylethanel-one,1-hydroxycyclohexylphenyl-ketone,2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1,2,4-diethylthioxanthone, 2-ethyl anthraquinone, and phenanthrene quinone; benzoinethers such as benzoin methyl ether, benzoin ethyl ether andbenzoinphenyl ether; benzoins such as methylbenzoin and ethyl benzoin;benzyl derivatives such as benzil dimethyl ketal; 2,4,5-triarylimidazoledimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer,2-(o-fluorophenyl)-4,5-phenylimidazole dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer,2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, and2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; acridinederivatives such as 9-phenyl acridine and1,7-bis(9,9′-acridinyl)heptane, and the like.

Also, to the first adhesive layer 12 may be added a photoinitiatorgenerating a base and radical by irradiation of radial rays. This givesthat a light-curable component is cured with radical generated byoptical illumination before or after dicing, as well as a base, which isa curing agent for a thermosetting resin, is generated in the system,and, after that, the first tacky-adhesive layer 12 can be effectivelysubjected to thermosetting reaction with heat history, whereby it is notnecessary to add separately initiators for light reaction andthermosetting reaction. As such a photoinitiator generating a base and aradical by irradiation of radial rays, for example,2-methyl-1(4-(methylthio)phenyl-2-morpholinopropane-1-one (Erasure 907manufactured by Ciba Speciality Chemicals),2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1-one (Erasure369 manufactured by Ciba Speciality Chemicals), hexaarylbisimidazolederivatives (phenyl group may be substituted by a sutstituent such ashalogen, alkoxy group, nitro group or cyano group) benzoisoxazolonederivative, and the like may be used.

Also, in order to improve the storage elasticity modulus of the firsttacky-adhesive layer 12 which is cured by radial rays or heat, forexample, a method in which the amount of the epoxy resin used isincreased, a method in which a cross-link density of the whole polymeris increased by using an epoxy resin having a high concentration ofglycidyl groups or a phenol resin having a high concentration ofhydroxyl groups, or a method in which a filler is added, may beemployed.

Further, in order to improve the reflow crack resistance, to the firsttacky-adhesive layer 12 may be added a high molecular weight resincompatible with a heat-polymerizable component. Such a high molecularweight resin is not particularly limited, and examples thereof mayinclude, for example, phenoxy resins, heat-polymerizable componentshaving a high molecular weight, heat-polymerizable components having anultrahigh molecular weight, and the like. They may be used alone or incombination thereof.

The amount of the heat-polymerizable component which is compatible witha high molecular weight resin used is preferably 40 parts by weight orless based on 100 parts by weight of the heat-polymerizable components.When the amount if within this range, it tends to be able to secure theTg of the heat-polymerizable component layer.

Also, in order to improve the handling and the thermal conductivity,control the melt viscosity and give the thixotropic nature, to the firsttacky-adhesive layer 12 may be added an inorganic filler. The inorganicfiller is not particularly limited, and examples thereof may include,for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate,magnesium carbonate, calcium silicate, magnesium silicate, calciumoxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminumborate whisker, boron nitride, crystalline silica, non-crystallinesilica, and the like. The shape of the filler is not particularlylimited. These fillers may be used alone or in combination thereof.

The compound generating the base by irradiation of radial rays is acompound generating a base when the radial ray is irradiated, and thegenerated base accelerates a curing reaction rate of the thermosettingresin, which is also referred to as a photobase generator. As the basesgenerated are preferably strongly basic compounds from the viewpoint ofreactivity and curing rate. In general, a pKa value, which is a log ofan acid dissociation constant, is used as a parameter of basicity, andbases having a pKa value in an aqueous solution of 7 or more arepreferable, more preferably 9 or more.

Also, as the above-mentioned compound generating a base by irradiationof radial rays, it is preferable to use compounds generating a base byoptical illumination having a weave length of 150 to 750 nm, and it ismore preferable to use compounds generating a base by opticalillumination having a weave length of 250 to 500 nm, in order toefficiently generate a base when general light source is used.

Examples of the compound generating the base by irradiation of radialrays may include imidazole derivatives such as imidazole, 2,4-dimethylimidazole, and 1-methyl imidazole; piperazine derivatives such aspiperazine, and 2,5-dimethyl piperazine; piperidine derivatives such aspiperidine, and 1,2-dimethyl piperidine; proline derivatives; trialkylamine derivatives such as trimethyl amine, tirethyl amine, andtriethanol amine; pyridine derivatives in which amino group or an alkylamino group is substituted at the 4th-position such as 4-methylaminopyridine, and 4-dimethyl aminopyridine; pyrrolidine derivativessuch as pyrrolidine and n-methylpyrrolidine; alicyclic amine derivativessuch as triethylene diamine, 1,8-diazabiscyclo(5,4,0)undecene-1(DBU);benzyl amine derivatives such as benzylmethyl amine, benzyldimethylamine, and benzyldiethyl amine, and the like.

It is desirable that the thickness of the first tacky-adhesive layer 12is within the range that while the sufficient adhesiveness to themounting substrate is secured, the sticking operation to thesemiconductor wafer and the subsequent dicing operation are not affectedthereby. From this viewpoint, the thickness of the first tacky-adhesivelayer 12 is preferably from 1 to 300 μm, more preferably from 5 to 150μm, particularly preferably from 10 to 100 μm. When the thickness isless than 1 μm, it tends to become difficult to secure the sufficientdie bond adhesion. When the thickness is more than 300 μm, the stickingoperation and the dicing operation tend to be impaired.

As a substrate film 14 constituting the adhesive sheet 1, the same filmor sheet as used in the release substrate 10 may be used. Examplesthereof may include, for example, polyester films such as polyethyleneterephthalate film; polyolefin films such as polytetrafluoroethylenefilm, polyethylene film, polypropylene film, polymethylpentene film andpolyvinyl acetate film; plastic films such as polyvinyl chloride filmand polyimide film, and the like. Further, as the substrate film 14,laminates composed of two or more layer of the films mentioned above maybe used.

Also, the thickness of the substrate film 14 is preferably from 10 to500 μm, more preferably from 25 to 100 μm, particularly preferably from30 to 50 μm.

The adhesive sheet 1 has the release substrate 10, the firsttacky-adhesive layer 12 and the substrate film 14, as described above.In the release substrate 10 of the adhesive sheet 1, incisions D areformed along the periphery of the plane shape of the first laminate 20comprising the first tacky-adhesive layer 12 and the substrate film 14from the surface of the release substrate 10 facing the firsttacky-adhesive layer 12 in the thickness direction of the releasesubstrate 10.

The incision depth d of this incision D is less than the thickness ofthe release substrate 10, and 25 μm or less. Here, in order to obtain abetter releasability, the incision depth d is more preferably 15 μm orless, still further preferably 10 μm or less, particularly preferably 5μm or less. As mentioned above, the closer to 0 μm the incision depth d,the better the releasability, and the depth of more than 0 μm and 0.5 μmor less is the most preferable.

When the incision depth d of the incision D is within theabove-mentioned range, in the adhesive sheet 1, then the firsttacky-adhesive layer 12 can be sufficiently inhibited from biting to theincision D. As a result, the interface between the release substrate 10and the first tacky-adhesive layer 12 is not sealed, and it is easy topeel off the first laminate 20 form the release substrate 10, wherebypeel defect can be sufficiently inhibited when the first laminate 20 isstuck to the adherend.

However, if the incision depth is brought close to 0 μm by using acurrent precut apparatus, it takes a long time for adjusting theapparatus and performing the precut processing, and, consequently, theproduction efficiency tends to lower. Accordingly, the incision depth dis preferably from 5 to 15 μm, form the viewpoint of the balance of theproduction efficiency and the inhibition of peel defect.

Also, in the adhesive sheet 1, it is preferable that a value of (d/a)satisfies a condition showing the following formula (1):0<(d/a)≦0.7  (1)wherein a (μm) is a thickness of the release substrate 10.

When the value of the above-mentioned (d/a) satisfies the conditionshowing the above-mentioned formula (1), the first tacky-adhesive layer12 can be sufficiently inhibited from biting to the incision D, and thepeel defect can be sufficiently inhibited. In order to fully obtain suchan effect, the upper limit of the value of (d/a) in the above-mentionedformula (1) is more preferably 0.5, still further preferably 0.3,particularly preferably 0.25, extremely preferably 0.15, the mostpreferably 0.1.

As mentioned above, the above-mentioned incision depth d refers to avalue obtained by measuring a depth of an incision D formed in therelease substrate 10 is measured with a cross-section observation usingan electron microscope at 10 points arbitrarily selected, and averagingthe obtained 10 values are averaged. It is preferable that all of thedepths of 10 incisions D arbitrarily selected and measured are withinthe above-mentioned range, from the viewpoint of the more sufficientinhibition of the peel defect.

Second Embodiment

FIG. 4 is a plane view showing a second embodiment of an adhesive sheetof the present invention, and FIG. 5 is a schematic cross-section viewof the adhesive sheet 2 shown in FIG. 4 which is cut along the lineA2-A2 in FIG. 4. As shown in FIG. 4 and FIG. 5, the adhesive sheet 2 hasa structure comprising a release substrate 10, a first tacky-adhesivelayer 12, a second tacky-adhesive layer 16 placed between a peripheralpart of the first tacky-adhesive layer 12 and the release substrate 10,and a substrate film 14. Also, the first tacky-adhesive layer 12 and thesubstrate film 14 are cut in pre-determined plane shapes, and are partlylaminated on the release substrate 10. Further, the secondtacky-adhesive layer 16 is cut in a pre-determined plane shape, and isplaced at a position where it will be stuck to a wafer ring when asecond laminate 22 comprising the substrate film 14, the firsttacky-adhesive layer 12 and the second tacky-adhesive layer 16 is stuckto a semiconductor wafer and the wafer ring. In the release substrate10, an annular incision D is formed along a plane shape of the secondlaminate 22 from a surface facing the first tacky-adhesive layer 12 andthe second tacky-adhesive layer 16, in a thickness direction of therelease substrate 10.

In the adhesive sheet 2, a incision depth d of the incision D formed inthe release substrate 10 is less than the thickness of the releasesubstrate 10, and 25 μm or less. Also, the incision depth d of theincision D and the (d/a) has the same preferable ranges as the incisiondepth d and the (d/a) of the adhesive sheet 1 in the first embodiment.

When such an adhesive sheet 2 is used, the second laminate 22 is peeledoff from the release substrate 10, the first tacky-adhesive layer 12 inthe second laminate 22 is stuck to a semiconductor wafer, and the secondtacky-adhesive layer 16 is stuck to a wafer ring.

In the adhesive sheet 2, the same materials as those described in theadhesive sheet 1 of the above-mentioned first embodiment may be used asthe release substrate 10, the first tacky-adhesive layer 12 and thesubstrate film 14.

The second tacky-adhesive layer 16 in the adhesive sheet 2 is formedfrom a resin such as an acrylic resin, a rubber, or a silicone resin.The thickness of the second tacky-adhesive layer 16 is preferably from 5to 50 μm.

When this second tacky-adhesive layer 16 is placed between theperipheral part of the first tacky-adhesive layer 12 and the releasesubstrate 10, in other word, it is placed at a position where it will bestuck to the wafer ring when the adhesive sheet 2 is used, it ispossible that the first tacky-adhesive layer 12 is not directly stick tothe wafer ring. If the first tacky-adhesive layer 12 is directly stuckto the wafer ring, it is necessary to adjust the tack strength of thefirst tacky-adhesive layer 12 to low tack strength such that the layeris not easily peeled off from the wafer ring. However, when the secondtacky-adhesive layer 16 is stuck to the wafer ring, such an adjustmentof the tack strength is not necessary. Consequently, the firsttacky-adhesive layer 12 can have sufficient high tack strength as wellas the second tacky-adhesive layer 16 has low tack strength such thatthe wafer ring can be easily peeled off, whereby the dicing operation ofthe semiconductor wafer and the subsequent peeling operation of thewafer ring can be efficiently performed. Further, since the tackstrength of the second tacky-adhesive layer 16 can be controlledsufficiently low, it is easy to generate starting points of peelingbetween the release substrate 10 and the second tacky-adhesive layer 16,whereby the second tacky-adhesive layer 16, the first tacky-adhesivelayer 12 and the substrate film 14 can be easily peeled off from therelease substrate 10, and thus the peel defect can be sufficientlyinhibited.

Third Embodiment

FIG. 6 is a plane view showing a third embodiment of an adhesive sheetof the present invention, and FIG. 7 is a schematic cross-section viewof the adhesive sheet 3 shown in FIG. 6 which is cut along the lineA3-A3 in FIG. 6. As shown in FIG. 6 and FIG. 7, the adhesive sheet 3 hasa structure comprising a release substrate 10, a first tacky-adhesivelayer 12, a second tacky-adhesive layer 16 placed between a peripheralpart of the first tacky-adhesive layer 12 and the release substrate 10,an intermediate layer 18 placed between the second tacky-adhesive layer16 and a substrate film 14, and the substrate film 14. The firsttacky-adhesive layer 12 and the substrate film 14 are cut inpre-determined plane shapes, and are partly laminated on the releasesubstrate 10. Further, the second tacky-adhesive layer 16 and theintermediate layer 18 are also cut in a pre-determined plane shape, andthey are placed at a position where it will be stuck to a wafer ringwhen a third laminate 24 comprising the substrate film 14, the firsttacky-adhesive layer 12, the intermediate layer 18, and the secondtacky-adhesive layer 16 is stuck to a semiconductor wafer and the waferring. In the release substrate 10, an annular incision D is formed alonga plane shape of the second laminate 22, from a surface facing the firsttacky-adhesive layer 12 and the second tacky-adhesive layer 16 in athickness direction of the release substrate 10.

In the adhesive sheet 3, an incision depth d of the incision D formed inthe release substrate 10 is less than the thickness of the releasesubstrate 10, and 25 μm or less. The incision depth d of the incision Dand the (d/a) has the same preferable ranges as the incision depth d andthe (d/a) of the adhesive sheet 1 in the first embodiment.

When the adhesive sheet 3 is used, the third laminate 24 is peeled offfrom the release substrate 10, the first tacky-adhesive layer 12 in thethird laminate 24 is stuck to the semiconductor wafer, and the secondtacky-adhesive layer 16 is stuck to the wafer ring.

In the adhesive sheet 3, the same materials as those described in theadhesive sheet 1 of the above-mentioned first embodiment may be used asthe release substrate 10, the first tacky-adhesive layer 12 and thesubstrate film 14, and the same materials as those described in theadhesive sheet 2 of the above-mentioned second embodiment may be used asthe second tacky-adhesive layer 16.

As the intermediate layer 18 in the adhesive sheet 3, for example, filmscomprising polyethylene, polypropylene, polyvinyl chloride, polyethyleneterephthalate, ethylene-vinyl acetate copolymer, ionomer resin oranother engineering plastic, a plate or foil of a metal may be used. Thethickness of such an intermediate layer 18 is preferably form 5 to 100μm.

In the adhesive sheet 3, similar to the adhesive sheet 2 in the secondembodiment, first, the second tacky-adhesive layer 16 is placed betweenthe peripheral part of the first tacky-adhesive layer 12 and the releasesubstrate 10, in other word, it is placed at a position where it will bestuck to the wafer ring when the adhesive sheet 2 is used. This givesthat it is possible that the first tacky-adhesive layer 12 is directlystuck to the wafer ring. When the first tacky-adhesive layer 12 hassufficient high tack strength as well as the second tacky-adhesive layer16 has low tack strength such that the wafer ring can be easily peeledoff, the dicing operation of the semiconductor wafer and the subsequentpeeling operation of the wafer ring can be more efficiently performed.

Further, in the adhesive sheet 3, since the intermediate layer 18 isplaced between the second tacky-adhesive layer 16 and the firsttacky-adhesive layer 12, it is possible to raise a degree of freedom ofchoice of materials for the second tacky-adhesive layer 16. For examplewhen the adhesive sheet 2 of the second embodiment is produced, it isnecessary to precut a second tacky-adhesive layer 16 after the secondtacky-adhesive layer 16 is laminated on the release substrate 10. Aninexpensive tacky-adhesive layer does not have self-supporting property,and therefore it can be difficult to completely peel off it from therelease substrate 10. However, as the adhesive sheet 3, when theintermediate layer 18 is provided, it is possible to easily remove thesecond tacky-adhesive layer 16 together with the intermediate layer 18on precut, whereby the efficiency of the working can be promoted as wellas the degree of freedom of the choice of the material for the secondtacky-adhesive layer 16 can be raised.

Production Method of Adhesive Sheet Forth Embodiment

A method for producing the adhesive sheet 1 concerning theabove-mentioned first embodiment, in accordance with the forthembodiment will be described.

FIG. 8 is a process chart showing series of production steps of theadhesive sheet 1. As shown in FIG. 8 (a), first, the first laminate 20comprising the first tacky-adhesive layer 12 and the substrate film 14is laminated on the release substrate 10 (a first laminating step).Next, as shown in FIGS. 8, (b) and (c), incisions are made with aprecutting blade C from an opposite surface F14 to the firsttacky-adhesive layer 12 side of the substrate film 14 until theincisions reach the release substrate 10 whereby the substrate film 14and the first tacky-adhesive layer 12 are cut in pre-determined planeshapes and the incisions D are formed in the release substrate 10 (afirst cutting step). The production of the adhesive sheet 1 is completedby this operation.

Here, in the first cutting step, the incision is made so that theincision depth d of the incision D is less than the thickness of therelease substrate 10 and 25 μm or less.

Now, each production step will be described in detail.

In the first laminating step, first, materials constituting the firsttacky-adhesive layer 12 are dissolved or dispersed in a solvent to givea vanish for forming the first tacky-adhesive layer, and the vanish iscoated on the substrate film 14, and after that, the solvent is removedby heating to form the first laminate 20.

Here, the above-mentioned solvents used in the production of vanish arenot particularly limited, so long as they can solve or disperse variousconstituting materials. In view of the volatility upon formation oflayers, it is preferable to use solvents having a relatively low boilingpoint such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol,2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone,toluene, and xylene. In order to improve the coating property, solventshaving a relatively high boiling point such as dimethyl acetoamide,dimethylformamide, N-methylpyrrolidone, and cyclohexanone can be used.These solvents may be used alone or in combination thereof. It is alsopossible to remove bubbles from the vanish by vacuum exhausting afterproducing the vanish.

For coating the vanish on the substrate film 14, known method may beused, and for example, a knife coating method, a roll coating method, aspray coating method, a gravure coating method, a bar coating method, acurtain coating method, and the like may be used.

Next, the first laminate 20 produced as above and the release substrate10 are laminated. Hereby the adhesive sheet before precut (hereinafterreferred to as a “precursor sheet”) is formed to complete the firstlaminating step.

Here, the lamination of the first laminate 20 and the release substrate10 may be performed in a conventional known manner such as a method inwhich a laminator is used.

Also, the precursor sheet can be produced by the following method. Forexample, a method in which after the vanish for forming the firsttacky-adhesive layer is coated on the release substrate 10, the solventis removed by heating to form the first tacky-adhesive layer 12, andthen the substrate film 14 is stuck to the obtained first tacky-adhesivelayer 12 using a laminator, or the like may be employed.

In the first cutting step, the incisions are made in the precursor sheetobtained as above from an opposite surface F14 to the firsttacky-adhesive layer 12 side of the substrate film 14 until theincisions reach the release substrate 10, whereby the first laminate 20comprising the first tacky-adhesive layer 12 and the substrate film 14in a pre-determined plane shape and the incision D is formed in therelease substrate 10.

Here, the cutting of the first laminate 20 can be performed using aprecutting blade C having a shape corresponding to the pre-determinedplane shape.

In the first cutting step, the incision is made so that the incisiondepth d of the incision D is less than the thickness of the releasesubstrate 10 and 25 μm or less. In order to obtain the adhesive sheet 1having better releasability, it is more preferable that the incisiondepth d of the incision D is 15 μm or less, still further preferably 10μm or less, particularly preferably 5 μm or less. As mentioned above,the closer to 0 μm the incision depth d, the better the releasability,and the depth of more than 0 μm and 0.5 μm or less is the mostpreferable. However, form the viewpoint of the balance of the productionefficiency and the inhibition of peel defect, the incision depth d ispreferably from 5 to 15 μm.

Also, in the first cutting step, it is preferable that a value of (d/a)satisfies a condition showing the following formula (1):0<(d/a)≦0.7  (1)wherein a (μm) is a thickness of the release substrate 10.

This gives that the adhesive sheet 1 capable of sufficiently inhibitingthe peel defect can be obtained. In order to fully obtain such aneffect, the upper limit of the value of (d/a) in the above-mentionedformula (1) is more preferably 0.5, still further preferably 0.3,particularly preferably 0.25, extremely preferably 0.15, the mostpreferably 0.1.

After that, if necessary, an unnecessary part is peeled off and removedfrom the first laminate 20 to obtain the desired adhesive sheet 1.

Fifth Embodiment

A method for producing the adhesive sheet 2 concerning theabove-mentioned second embodiment in accordance with the fifthembodiment will be described.

FIG. 9 is a process chart showing series of production steps of theadhesive sheet 2. As shown in FIG. 9 (a), first, the secondtacky-adhesive layer 16 is laminated on the release substrate 10. Next,incision are made in the second tacky-adhesive layer 16 using aprecutting blade C, and the second tacky-adhesive layer 16 is partlyremoved to form, as shown in FIG. 9 (b), an exposed surface F10 on sideof the release substrate 10 facing the second tacky-adhesive layer 16 (asecond laminating step). After that, as shown in FIG. 9 (c), the firsttacky-adhesive layer 12 and the substrate film 14 are laminated on theexposed surface F10 of the release substrate 10 and the secondtacky-adhesive layer 16 (a third laminating step). Next, as shown inFIG. 9 (d) and (e), incisions are made with a precutting blade C from anopposite surface F14 to the first tacky-adhesive layer 12 in thesubstrate film 14 until the incisions reach the release substrate 10,whereby the substrate film 14, the first tacky-adhesive layer 12 and thesecond tacky-adhesive layer 16 are cut in pre-determined plane shapes aswell as the incision D is formed in the release substrate 10 (a secondcutting step). The production of the adhesive sheet 2 is completed bythis operation.

Here, in the second cutting step, the first tacky-adhesive layer 12 isbrought contact with the exposed surface F10 of the release substrate 10within a range of the above-mentioned pre-determined plane shape (withinthe range of the inside of the above-mentioned incision D), and thecutting is performed at a peripheral part within the above-mentionedrange so that the first tacky-adhesive layer 12 is brought contact withthe second tacky-adhesive layer 16 as well as the incisions are made sothat the incision depth d of the incision D is less than the thicknessof the release substrate 10 and 25 μm or less.

Now, each production step will be described in detail.

In the second laminating step, materials constituting the secondtacky-adhesive layer 16 are dissolved or dispersed in a solvent to givea vanish for forming the second tacky-adhesive layer, and the vanish iscoated on the substrate film 14, and after that, the solvent is removedby heating to form the second tacky-adhesive layer 16.

Subsequently, the incision are made in the second tacky-adhesive layer16 as obtained above using a precutting blade C from an opposite surfaceF16 to the release substrate 10 of the second tacky-adhesive layer 16until the incisions reach the release substrate 10, and the secondtacky-adhesive layer 16 is partly removed from the release substrate 10to form an exposed surface F10 on side of the release substrate 10facing the second tacky-adhesive layer 16. By this operation, the secondtacky-adhesive layer 16 is partly laminated on the release substrate 10to complete the second laminating step.

In the third laminating step, first, materials constituting the firsttacky-adhesive layer 12 are dissolved or dispersed in a solvent to givea vanish for forming the first tacky-adhesive layer, and the vanish iscoated on the substrate film 14, and after that, the solvent is removedby heating to form the second laminate 20. Here, the first laminate 20can be produced in the same manner as in the above-mentioned forthembodiment.

Next, the first laminate 20 obtained as above is laminated on theexposed surface F10 of the release substrate 10 and the secondtacky-adhesive layer 16. By this operation, the adhesive sheet beforeprecut (the precursor sheet) is formed and the third laminating step iscompleted.

In the second cutting step, the incisions are made in the precursorsheet obtained above from the opposite surface F14 to the firsttacky-adhesive layer 12 of the substrate film 14 until the incisionsreach the release substrate 10, whereby the substrate film 14, the firsttacky-adhesive layer 12 and the second tacky-adhesive layer 16 are cutin pre-determined plane shapes as well as the incision D is formed inthe release substrate 10.

Here, the cutting of the substrate film 14, the first tacky-adhesivelayer 12 and the second tacky-adhesive layer 16 can be performed using aprecutting blade C having a shape corresponding to the pre-determinedplane shape.

The preferable range of the incision depth d of the incision D formed inthis second cutting step and the (d/a) are the same as in theabove-mentioned forth embodiment.

After that, if necessary, unnecessary parts are peeled off and removedfrom the substrate film 14, the first tacky-adhesive layer 12 and thesecond tacky-adhesive layer 16 to obtain the desired adhesive sheet 2wherein the second laminate 22 comprising the second tacky-adhesivelayer 16, the first tacky-adhesive layer 12 and the substrate film 14 islaminated on the release substrate 10.

Sixth Embodiment

A method for producing the adhesive sheet 3 concerning theabove-mentioned third embodiment in accordance with the sixth embodimentwill be descried.

FIG. 10 is a process chart showing series of production steps of theadhesive sheet 3. As shown in FIG. 10 (a), first, the secondtacky-adhesive layer 16 and the intermediate layer 18 are laminated onthe release substrate 10. Next, incisions are made in the secondtacky-adhesive layer 16 and the intermediate layer 18 with a precuttingblade C, and the second tacky-adhesive layer 16 and the intermediatelayer are partly removed to form, as shown in FIG. 10 (b), an exposedsurface F10 facing the second tacky-adhesive layer 16 of the releasesubstrate 10 (a fourth laminating step). After that, as shown in FIG. 10(c), the first tacky-adhesive layer 12 and the substrate film 14 arelaminated on the exposed surface F10 of the release substrate 10 and theintermediate layer 18 (a fifth laminating step). Next, as shown in FIG.10 (d) and (e), incisions are made with a precutting blade C from anopposite surface F14 to the first tacky-adhesive layer 12 of thesubstrate film 14 until the incisions reach the release substrate 10,whereby the substrate film 14, the first tacky-adhesive layer 12, theintermediate layer 18 and the second tacky-adhesive layer 16 are cut inpre-determined plane shapes as well as the incisions D are formed on therelease substrate 10 (a third cutting step). By this operation, theproduction of the adhesive sheet 3 is completed.

Here, in the third cutting step, the first tacky-adhesive layer 12 isbrought contact with the exposed surface F10 of the release substrate 10within a range of the above-mentioned pre-determined plane shape (withinthe range of the inside of the above-mentioned incision D), and thecutting is performed at a peripheral part within the above-mentionedrange so that the first tacky-adhesive layer 12 is brought contact withthe intermediate layer 18 as well as the incision are made so that theincision depth d of the incision D is less than the thickness of therelease substrate 10 and 25 μm or less.

Now, each production step will be described in detail.

In the forth laminating step, materials constituting the secondtacky-adhesive layer 16 are dissolved or dispersed in a solvent to givea vanish for forming the second tacky-adhesive layer, and the vanish iscoated on the release substrate 10, and after that, the solvent isremoved by heating to form the second tacky-adhesive layer 16. Next,materials constituting the intermediate layer 18 are dissolved ordispersed in a solvent to give a vanish for forming the intermediatelayer, and the vanish is coated on the second tacky-adhesive layer 16,and after that, the solvent is removed by heating to form theintermediate layer 16.

Subsequently, incisions are made in the second tacky-adhesive layer 16and the intermediate layer 18 obtained above with a precutting blade Cfrom an opposite surface F18 to the second tacky-adhesive layer 16 ofthe intermediate layer 18 until the incisions reach the releasesubstrate 10, and the second tacky-adhesive layer 16 and theintermediate layer 18 are partly removed from the release substrate 10,whereby an exposed surface F10 is formed on a surface of the releasesubstrate 10 facing the second tacky-adhesive layer 16. By thisoperation, the second tacky-adhesive layer 16 and the intermediate layer18 are partly laminated on the release substrate 10, and the forthlaminating step is completed.

In the fifth laminating step, first, materials constituting the firsttacky-adhesive layer 12 are dissolved or dispersed in a solvent to givea vanish for forming the first tacky-adhesive layer, and the vanish iscoated on the substrate film 14, and after that, the solvent is removedby heating to form the first laminate 20. Here, the first laminate 20can be produced in the same manner as in the above-mentioned forth 4embodiment.

Next, the first laminate 20 produced above is laminated on the exposedsurface F10 of the release substrate 10 and the intermediate layer 18.By this operation, the adhesive sheet before precut (the precursorsheet) is formed and the fifth laminating step is completed.

In third cutting step, the incisions are made in the precursor sheetobtained above from the opposite surface F14 to the first tacky-adhesivelayer 12 of the substrate film 14 until the incisions reach the releasesubstrate 10, whereby the substrate film 14, the first tacky-adhesivelayer 12, the intermediate layer 18 and the second tacky-adhesive layer16 are cut in pre-determined plane shapes as well as the incisions D areformed in the release substrate 10.

Here, the cutting of the substrate film 14, the first tacky-adhesivelayer 12, the intermediate layer 18 and the second tacky-adhesive layer16 can be performed using a precutting blade C having a shapecorresponding to the pre-determined plane shape.

The preferable range of the incision depth d of the incision D formed inthis third cutting step and the (d/a) are the same as in theabove-mentioned forth embodiment.

After that, if necessary, unnecessary parts are peeled off and removedfrom the substrate film 14, the first tacky-adhesive layer 12, theintermediate layer 18 and the second tacky-adhesive layer 16 to obtainthe desired adhesive sheet 3 in which the third laminate 24 comprisingthe second tacky-adhesive layer 16, the intermediate layer 18, the firsttacky-adhesive layer 12 and the substrate film 14 is formed on therelease substrate 10.

As mentioned above, the preferable embodiments of the adhesive sheets ofthe present invention and the method for producing the adhesive sheetwere descried in detail, but the present invention is not limited tothese embodiment.

[Production Method of Semiconductor Device]

A method for producing a semiconductor device using the adhesive sheetdescribed above will be described using FIGS. 11 and 12. In thefollowing description, a case in which as an adhesive sheet, theadhesive sheet 2 in the above-mentioned second embodiment is used willbe described.

FIG. 11 is a process chart showing series of steps for sticking a secondlaminate 22 of the adhesive sheet 2 to a semiconductor wafer 32. Asshown in FIG. 11 (a), in the adhesive sheet 2, the release substrate 10serves as a carry film, and the sheet 2 is supported by two rolls 62 and66, and a cuneate member 64. The adhesive sheet 2 is wound in a state inwhich its one end is attached to a cylindrical core 44 to form a firstroll 42, and its other end is attached to a cylindrical core 54 to forma second roll 52. To the core 54 of the second roll 52 is attached acore driving motor for rotating the core 54 (not shown in Fig.). Thisgives that after the second laminate 22 of the adhesive sheet 2 ispeeled off, the resulting release substrate 10 is wound around the core54 at a pre-determined speed.

First, when the core driving motor is rotated, the core 54 of the secondroll 52 is rotated, whereby the adhesive sheet 2 wound around the core44 of the first roll 42 is drawn outward from the first roll 42. Thedrawn adhesive sheet 2 is introduced on the disc-shaped semiconductorwafer 32 placed on the mobile stage 36, and the wafer ring 34 placed soas to surround the semiconductor wafer 32.

Next, the second laminate 22 comprising the substrate film 14, the firsttacky-adhesive layer 12 and the second tacky-adhesive layer 16 is peeledoff from the release substrate 10. At this time, the cuneate member 64is brought contact with the release substrate 10 from the releasesubstrate 10 side of the adhesive sheet 2, whereby the release substrate10 is bent to the member 64 side at a sharp angle. As a result, basepoints for peeling are formed between the release substrate 10 and thesecond laminate 22. Further, in order to more efficiently form the basepoints for peeling, air is blown at a boundary surface between therelease substrate 10 and the second laminate 22.

After base points for peeling are formed between the release substrate10 and the second laminate 22, as mentioned above, to which the secondlaminate 22 is stuck so that the second tacky-adhesive layer 16 closelycontacts the wafer ring 34 and the first tacky-adhesive layer 12 closelycontacts the semiconductor wafer 32, as shown in FIG. 11 (b). At thistime, the second laminate 22 is joined with pressure to thesemiconductor wafer 32 and the wafer ring 34 by the roll 68. After that,as shown in FIG. 11 (c), the lamination of the second laminate 22 on thesemiconductor wafer 32 and the wafer ring 34 is completed.

According to the above-mentioned procedure, the lamination of the secondlaminate 22 to the semiconductor wafer 32 can be continuously performedin an automatic step. Examples of the apparatus for laminating thesecond laminate 22 to the semiconductor wafer, used in theabove-mentioned procedure, may include, for example, RAD-2500™manufactured by Lintec Corporation, and the like.

When the second laminate 22 is stuck to the semiconductor wafer 32according to this step, the base points for peeling between the releasesubstrate 10 and the second laminate 22 (the bases points for peelingbetween the release substrate 10 and the second tacky-adhesive layer 16)can be easily formed by using the adhesive sheet 2, and therefore theoccurrence of the peel defect can be fully inhibited.

Next, the semiconductor wafer 32 on which the second laminate 22 islaminated in the above-mentioned step (FIG. 12 (a)) is diced, as shownin FIG. 12 (b), with a dicing blade G into a necessary size to obtain asemiconductor element 33 to which the first tacky-adhesive layer 12adheres. Further, in this process, steps for drying or washing or thelike may be performed. At this time, since the semiconductor wafer 32 issufficiently stuck and held to the substrate film 14 through the firsttacky-adhesive layer 12, falling of the semiconductor wafer 32 and thediced semiconductor element 33 is sufficiently inhibited during theabove-mentioned steps.

Next, high energy beams such as radial rays are irradiated to the firsttacky-adhesive layer 12 to cure a part of the first tacky-adhesive layer12 with polymerization. In this case, in order to accelerate the curingreaction, the layer may be heated at the same time of after theirradiation of the high energy beams.

The high energy beams are irradiated to the first tacky-adhesive layer12 from a surface where the first tacky-adhesive layer 12 of thesubstrate film 14 is not formed. It is necessary that the substrate film14 is light-transmissive, when ultraviolet ray is used as the highenergy beams, accordingly. When electron beam is used as the high energybeams, the substrate film 14 is not necessary light-transmissive.

After the irradiation of the high energy beams, as shown in FIG. 12 (c),semiconductor element 33 to be picked-up is picked-up with, for example,a suction collet. At this time, the semiconductor element 33 to bepicked-up can be knocked up with, for example, a needle rod from theunder surface of the substrate film 14. By curing the firsttacky-adhesive layer 12, the peeling easily occurs at an interfacebetween the first tacky-adhesive layer 12 and the substrate film 14,when the semiconductor element 33 is picked-up, and the picking-up isperformed in the state in which the first tacky-adhesive layer 12adheres to the under surface of the semiconductor element 33.

Next, as shown in FIG. 12 (d), the semiconductor element 33 to which thefirst tacky-adhesive layer 12 adheres is mounted on the support memberfor mounting a semiconductor element 71 through the first tacky-adhesivelayer 12, which is heated. The adhesion of the first tacky-adhesivelayer 12 is expressed by heating, and the adhesion between thesemiconductor element 33 and the support member for mounting asemiconductor element 71 is completed.

After that, if necessary, a wire stick step and a sealing step areperformed to produce a semiconductor device.

[Semiconductor Device]

FIG. 13 is schematic cross-section view showing one embodiment of asemiconductor element of the present invention produced according to theabove-mentioned production method of the semiconductor device.

As shown in FIG. 13, in a semiconductor device 100, two semiconductorelements 33 is laminated on an organic substrate 70, which will be asupport member for mounting a semiconductor element, through a firsttacky-adhesive layer 12. On an organic substrate are formed a circuitpattern 74 and a terminal 76. The circuit pattern is attached to the twosemiconductor element 33 with a wire stick 78. These are sealed with asealer 80 to form the semiconductor device 100. The semiconductor device100 is produced using the adhesive sheet 2 produced by the method forproducing a semiconductor device of the above-mentioned presentinvention.

Although the preferable embodiments of the method for producing thesemiconductor device of the present invention and the semiconductordevice were described in detail as above, the present invention is notlimited to these embodiments. For example, in the embodiment in whichthe adhesive sheet 2 is used in the method for producing a semiconductordevice was described above, the adhesive sheet 1 or the adhesive sheet 3may be used as the adhesive sheet.

Adhesive Sheet Seventh Embodiment

FIG. 16 is a plane view showing a seventh embodiment of an adhesivesheet of the present invention, and FIG. 17 is a schematic cross-sectionview of the adhesive sheet 201 shown in FIG. 16 which is cut along theline A11-A11 in FIG. 16. As shown in FIG. 16 and FIG. 17, an adhesivesheet 201 has a structure in which a release substrate 212, an adhesivelayer 214, a tacky layer 222 and a substrate film 224 are laminated inorder. A laminate 210 comprising the adhesive layer 214, and a tackyfilm 220 comprising the tacky layer 222 and the substrate film 224 arecut in pre-determined plane shapes, and they are partly laminated on therelease substrate 212. Further, in the release substrate 212, a firstincision D1 is formed along a periphery of a plane shape of the laminate210 from a surface bringing contact with the adhesive layer 214 in athickness direction of the release substrate 212.

Here, the above-mentioned pre-determined plane shape of the laminate 210is not particularly limited so long as the laminate 210 is partlylaminated on the release substrate 212. It is preferable that theabove-mentioned pre-determined plane shape of the laminate 210 is thesame as the pre-determined plane shape of the first laminate 20.

In the adhesive sheet 201, an incision depth d1 of the first incision D1formed on release substrate 212 is less than the thickness of therelease substrate 212 and 25 μm or less.

When such an adhesive sheet 201 is used, the laminate 210 is peeled offform the release substrate 212, and the laminate 210 is stuck to anadherend such as a semiconductor wafer through the adhesive layer 214.

Now each layer constituting the adhesive sheet 201 will be described indetail.

The release substrate 212 serves as a carry film when the adhesive sheet201 is used. As the release substrate 212, the same material as in therelease substrate 10 may be used.

Also, it is preferable that the surface bringing contact with theadhesive layer 214 of the release substrate 212 is surface-treated witha release agent such as a silicone releasing agent, afluorine-containing releasing agent, a long-chain alkyl acrylatereleasing agent.

The thickness of the release substrate 212 may be suitably selectedwithin a range where the workability upon using is not impaired, and thethickness is preferably 10 to 500 μm, more preferably 25 to 100 μm,particularly preferably 30 to 50 μm.

In the adhesive layer 214, known thermosetting adhesive agents,photocurable adhesive agents, thermoplastic adhesive agents andoxygen-reactive adhesive agents may be used. They may be used alone orin combination thereof.

As the above-mentioned thermoplastic adhesive agent, resins havingthermal plasticity, and resins having thermal plasticity at least in itsuncured state and forming a cross-linked structure after heating can beused. Examples of such a resin may include, for example, polyimideresins, polyamide resins, polyether imide resins, polyamide imideresins, polyester resins, polyester imide resins, phenoxy resins,polysulfone resins, polyether sulfone resins, polyphenylene sulfideresins, polyether ketone resins, and the like. Polymers including afunctional monomer as a monomer unit may be used. Examples of thefunctional group in the functional monomer may include glycidyl group,acryloyl group, methacryloyl group, hydroxyl group, carboxyl group,isocyanurate group, amino group, amido group, and the like. Morespecifically, glycidyl group-containing (meth)acrylic copolymersincluding a functional monomer such as glycidyl acrylate or glycidylmethacrylate as a monomer unit may be used. In the present invention,the (meth)acrylic copolymer includes both of acrylic copolymer andmethacrylic copolymer.

As the above-mentioned glycidyl group-containing (meth)acryliccopolymer, for example, (meth)acrylic ester copolymers and acrylicrubbers may be used, and the acrylic rubbers are more preferable. Theacrylic rubber comprises, as a main component, an acrylic ester, whichis a rubber mainly comprising a copolymer including butyl acrylate andacrylonitrile, or a copolymer including ethyl acrylate andacrylonitrile. Examples of the glycidyl group-containing (meth)acryliccopolymer may include, for example, HTR-860P-3™ manufactured by NagaseChemtex Corporation, and the like.

Examples of the above-mentioned functional monomer other than glycidylacrylate and glycidyl methacrylate may include, for example,ethyl(meth)acrylate, butyl (meth)acrylate, and the like. They may bealone or in combination thereof. In the present invention, theethyl(meth)acrylate includes both ethyl acrylate and ethyl methacrylate.

The above-mentioned thermosetting adhesive agents are not particularlylimited so long as they are thermosetting resins which are cured byheating to show adhesive action. Examples thereof includes compoundshaving a functional group such as glycidyl group, acryloyl group,methacryloyl group, hydroxyl group, carboxyl group, isocyanurate group,amino group, or amido group. They may be used alone or in combinationthereof. More specifically, example thereof include epoxy resins,acrylic resins, silicone resins, phenol resins, thermosetting polyimideresins, polyurethane resins, melamine resins, urea resins, and the like.

The above-mentioned epoxy resins are not particularly limited so long asthey are cured to show adhesive action. For example, difunctional epoxyresins such as bisphenol A type epoxy resins, novolac type epoxy resinssuch as phenol-novolac type epoxy resin and cresol novolac type epoxyresin may be used. Generally known resins such as polyfunctional epoxyresins, glycidyl amine type epoxy resins, heteroring-containing epoxyresins, and alicyclic epoxy resins may also be used. They may be usedalone or in combination thereof.

When the epoxy resin is used, it is preferable to use a curing agent forepoxy resin. As the curing agent for epoxy resin may be used knowncuring agents generally used, and examples thereof include amines,polyamides, acid anhydrides, polysulfides, boron trifluorides,dicyandiamides, bisphenols including two or more phenolic hydroxylgroups in one molecule such as bisphenol A, bisphenol F, and bisphenolS, phenol resins such as phenol-novolac resins, bisphenol A-novolacresins and creosol novolac resin, and the like. These curing agents forepoxy resin may be used alone or in combination thereof.

It is desirable that the thickness of the adhesive layer 214 is adjustedto a range in which the adhesive strength to a substrate for mounting isfully secured as well as the laminating operation to a semiconductorwafer and the subsequent dicing operation are not affected. From theseviewpoints, the thickness of the adhesive layer 214 is preferably from 1to 300 μm, more preferably from 5 to 150 μm, particularly preferablyfrom 10 to 100 μm. When the thickness is less than 1 μm, it tends tobecome difficult to secure sufficient die bond adhesive strength. Whenthe thickness is more than 300 μm, failures such as affection to adicing operation tend to generate.

The tacky film 220 is has a structure in which the tacky layer 222 isformed on the substrate film 224.

As the substrate film 224 constituting this tacky film 220, the samefilms or sheets as used in the release substrate 212 may be used.

Examples thereof may include polyester films such as polyethyleneterephthalate film; polyolefin films such as polytetrafluoroethylenefilm, polyethylene film, polypropylene film, polymethylpentene film, andpolyvinyl acetate film; plastic films such as polyvinyl chloride filmand polyimide film, and the like. Further, laminates comprising twolayers or more composed of these films may be used as the substrate film224.

The thickness of the substrate film 224 is preferably from 10 to 500 μm,more preferably from 25 to 100 μm, particularly preferably from 30 to 50μm.

It is preferable that the tacky layer 222 constituting the tacky film220 is cured by high energy beams such as ultraviolet ray or radialrays, or heat (to lower the tack strength), more preferably it is curedby high energy beams, particularly preferably it is cured by ultravioletray.

As The tack agent constituting such a tacky layer 222, various typeshave hitherto been known. It is preferable that a suitable tack agent bywhich the tack strength to the adhesive layer 214 is lowered byirradiation of high energy beams is selected from among the varioustypes.

Examples of the above-mentioned tack agent may includes, for example,compounds having diol group, isocyanate compounds, urethane(meth)acrylate compounds, diamine compounds, urea methacrylatecompounds, high energy beams polymerizable copolymer having anethylenically unsaturated group at the side chains, and the like. Theymay be used alone or in combination thereof.

The thickness of the tacky layer 222 is preferably from 1 to 100 μm,more preferably 2 to 20 μm, particularly preferably from 3 to 10 μm.When the thickness is less than 1 μm, it tends to become difficult to besecure a sufficient tack strength, and semiconductor chips can bescattered while dicing. When the thickness is more than 100 μm, thethickness of the adhesive sheet 201 is too thick as a whole, andtherefore, it tends to become difficult to stick it to an adherend.

The adhesive sheet 201 has the release substrate 212, the adhesive layer214, the tacky layer 22 and the substrate film 224, as mentioned above.In the release substrate 212 of the adhesive sheet 1, the first incisionD1 is formed along a periphery of a plane shape of the laminate 210comprising the adhesive layer 214, the tacky layer 22 and the substratefilm 224 from a surface bringing contact with the adhesive layer 214 onthe release substrate 212 in a thickness direction of the releasesubstrate 212.

The incision depth d1 of the first incision D1 is less than thethickness of the release substrate 212 and 25 μm or less. Here, in orderto obtain better releasability, the incision depth d1 is more preferably15 μm or less, still further preferably 10 μm or less, particularlypreferably 5 μm or less. As mentioned above, the closer to 0 μm theincision depth d1, the better the releasability, and it is the mostpreferable that it is more than 0 μm and 0.5 μm or less.

When the incision depth d1 of the first incision D1 is within theabove-mentioned range, the adhesive layer 214 and the tacky layer 222 inthe adhesive sheet 201 can be sufficiently inhibited from biting to thefirst incision D1. As a result, the interface between the releasesubstrate 212 and the adhesive layer 214 is not sealed, the laminate 210is easily peeled off from the release substrate 212, whereby the peeldefect can be sufficiently inhibited when the laminate 210 is stuck tothe adherend.

However, if the incision depth is brought close to 0 μm by using acurrent precut apparatus, it takes a long time for adjusting theapparatus and performing the precut processing, and, consequently, theproduction efficiency tends to lower. Accordingly, the incision depth dis preferably from 5 to 15 μm, form the viewpoint of the balance of theproduction efficiency and the inhibition of peel defect.

Also, in the adhesive sheet 201, it is preferable that a value of (d1/a)satisfies a condition showing the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate 212.

When the value of the above-mentioned (d1/a) satisfies the conditionshowing the above-mentioned formula (2), the adhesive layer 214 and thetacky layer 222 can be more sufficiently inhibited from biting to thefirst incision D1, and peel defect can be more sufficiently inhibited.In order to fully obtain such an effect, the upper limit of the value of(d1/a) in the above-mentioned formula (2) is more preferably 0.5, stillfurther preferably 0.3, particularly preferably 0.25, extremelypreferably 0.15, the most preferably 0.1.

As mentioned above, the above-mentioned incision depth d1 refers to avalue obtained by measuring a depth of an incision D1 formed in therelease substrate 212 is measured with a cross-section observation usingan electron microscope at 10 points arbitrarily selected, and averagingthe obtained 10 values are averaged. It is preferable that all of thedepths of 10 incisions D1 arbitrarily selected and measured are withinthe above-mentioned range, from the viewpoint of the more sufficientinhibition of the peel defect. The same holds for the incision depth d2of the below-mentioned second incision D2.

Eighth Embodiment

FIG. 18 is a plane view showing an eighth embodiment of an adhesivesheet of the present invention, and FIG. 19 is a schematic cross-sectionview of the adhesive sheet 202 shown in FIG. 18 which is cut along theline A12-A12 in FIG. 18. As shown in FIG. 18 and FIG. 19, an adhesivesheet 202 has a structure in which a release substrate 212, an adhesivelayer 214, a tacky layer 222, and a substrate film 224 are laminated inorder. The adhesive layer 214 is cut in a pre-determined first planeshape, and is partly laminated on the release substrate 212. In therelease substrate 212, the first incision D1 is formed along the firstplane shape of the adhesive layer 214 from a surface bringing contactwith the adhesive layer 214 in the thickness direction of the releasesubstrate 212. The tacky layer 222 covers the adhesive layer 214, andlaminated around the adhesive layer 214 so as to bring contact with therelease substrate 212. A tacky film 220 comprising the tacky layer 222and the substrate film 224 is cut in a pre-determined second planeshape. In the release substrate 212, a second incision D2 is formedalong a periphery of a second plane shape of the tacky film 220 from asurface bringing contact with the tacky layer 222 in a thicknessdirection of the release substrate 212.

In the adhesive sheet 202, the incision depth d1 of the first incisionD1 and incision depth d2 of the second incision D2, which incisions areformed in the release substrate 212, are less than the thickness of therelease substrate 212 and 25 μm or less.

Here, in order to obtain better releasability, the incision depth d1 ofthe first incision D1 and the incision depth d2 of the second incisionD2 are more preferably 15 μm or less, still further preferably 10 μm orless, particularly preferably 5 μm or less. As mentioned above, thecloser to 0 μm the incision depth d1, the better the releasability, andit is the most preferable that the depths are more than 0 μm and 0.5 μmor less. From the viewpoint of the balance between the efficiency andthe inhibition of peel defect, the incision depths d1 and d2 arepreferably from 5 to 15 μm.

Also, in the adhesive sheet 202, it is preferable that a value of (d1/a)satisfies a condition showing the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate 212.

Further, it is preferable that a value of (d2/a) satisfies a conditionshowing the following formula (3):0<(d2/a)≦0.7  (3)wherein a (μm) is a thickness of the release substrate 212.

When the value of the above-mentioned (d1/a) satisfies the conditionshowing the above-mentioned formula (2), the adhesive layer 214 and thetacky layer 222 can be more sufficiently inhibited from biting to thefirst incision D1, and peel defect can be more sufficiently inhibited.When the value of the above-mentioned (d2/a) satisfies the conditionshowing the above-mentioned formula (3), the tacky layer 222 can be moresufficiently inhibited from biting to the second incision D2, and peeldefect can be more sufficiently inhibited. In order to fully obtain sucheffects, the upper limits of the value of (d1/a) in the above-mentionedformula (2) and the values of (d2/a) in the above-mentioned formula (3)are more preferably 0.5, still further preferably 0.3, particularlypreferably 0.25, extremely preferably 0.15, the most preferably 0.1.

In the adhesive sheet 202, the same materials as in the adhesive sheet201 concerning the above-mentioned seventh embodiment may be used as therelease substrate 212, the adhesive layer 214, the tacky layer 222 andthe substrate film 224.

When wafer ring is used in the dicing operation of the semiconductorwafer is subjected to dicing, the adhesive sheet 202 having such astructure makes the tacky layer 222 closely contact to the wafer ring,whereby the dicing can be easily operated.

When the incision depth d1 of the first incision D1 and the incisiondepth d2 of the second incision D2 in the release substrate 212 of theadhesive sheet 202 are within the above-mentioned range, the adhesivelayer 214 can be sufficiently inhibited from biting to the firstincision D1, and the tacky layer 222 can also be inhibited from bitingto the second incision D2. As a result, the interface between therelease substrate 212 and the adhesive layer 214, and the interfacebetween the release substrate 212 and the tacky layer 222 are notsealed, and the laminate 210 can be easily peeled off from the releasesubstrate 212, and the peel defect can be sufficiently inhibited whenthe laminate 210 is stuck to the adherend.

Ninth Embodiment

FIG. 20 is a plane view showing a ninth embodiment of an adhesive sheetof the present invention, and FIG. 21 is schematic cross-section view ofthe adhesive sheet 203 shown in FIG. 20 which is cut along the lineA13-A13 in FIG. 20. As shown in FIG. 20 and FIG. 21, an adhesive sheet203 has a structure in which a release substrate 212, an adhesive layer214, a tacky layer 222 and a substrate film 224 are laminated in order.The adhesive layer 214 is cut in a pre-determined plane shape, and ispartly laminated on the release substrate 212. In the release substrate212, a first incision D1 is formed on a periphery of a plane shape ofthe adhesive layer 214 from a surface bringing contact with the adhesivelayer 214 in a thickness direction of the release substrate 212. Also,the tacky layer 222 and the substrate film 224 cover the adhesive layer214, and they are laminated so that the tacky layer 222 is broughtcontact with the release substrate 212 around the adhesive layer 214.

In such a adhesive sheet 203, a thickness of an incision depth d1 of afirst incision D1 formed on the release substrate 212 is less than thethickness of the release substrate 212 and 25 μm or less.

Here, in order to obtain better releasability, the incision depth d1 ofthe first incision D1 is more preferably 15 μm or less, still furtherpreferably 10 μm or less, particularly preferably 5 μm or less. Asmentioned above, the closer to 0 μm the incision depth d1, the betterthe releasability, and it is the most preferable that the depth is morethan 0 μm and 0.5 μm or less. The incident depth d1 is preferably from 5μm to 15 μm from the viewpoint of the production efficiency and theinhibition of peel defect.

Also, in the adhesive sheet 203, it is preferable that a value of (d1/a)satisfies a condition showing the following formula (2):0<(d1/a)≦0.7  (2).

When the value of the above-mentioned (d1/a) satisfies the conditionshowing the above-mentioned formula (2), the adhesive layer 214 and thetacky layer 222 can be more sufficiently inhibited from biting to thefirst incision D1, and peel defect can be more sufficiently inhibited.In order to fully obtain such an effect, the upper limits of the valueof (d1/a) in the above-mentioned formula (2) is more preferably 0.5,still further preferably 0.3, particularly preferably 0.25, extremelypreferably 0.15, the most preferably 0.1.

In the adhesive sheet 203, the same materials as in the adhesive sheet201 concerning the above-mentioned seventh embodiment may be used as therelease substrate 212, the adhesive layer 214, the tacky layer 222 andthe substrate film 224.

When the incision depth d1 of the first incision D1 in the releasesubstrate 212 of the adhesive sheet 203 is within the above-mentionedrange, the adhesive layer 214 can be sufficiently inhibited from bitingto the first incision D1. As a result, the interface between the releasesubstrate 212 and the adhesive layer 214 is not sealed, and the laminate210 can be easily peeled off from the release substrate 212, and thepeel defect can be sufficiently inhibited when the laminate 210 is stuckto the adherend.

Production Method of Adhesive Sheet Tenth Embodiment

A method for producing the adhesive sheet 201 concerning theabove-mentioned seventh embodiment, in accordance with the tenthembodiment will be described.

The adhesive sheet 201 is produced by a method comprising a firstlaminating step in which the adhesive layer 214, the tacky layer 222 andthe substrate film 224 are laminated on the release substrate 212; and afirst cutting step in which an incision is made from an opposite surfaceto a side bringing contact with the tacky layer 222 of the substratefilm 224, until the incision reaches to the release substrate 212,whereby the adhesive layer 214, the tacky layer 222 and the substratefilm 224 are cut in pre-determined plane shapes, as well as the firstincision D1 is formed in the release substrate 212.

Here, in the first cutting step, the incision is made so that theincision depth d1 of the first incision D1 is less than the thickness ofthe release substrate 212 and is 25 μm or less.

Now, each production step will be described in detail.

In the first laminating step, first, materials constituting the adhesivelayer 214 are dissolved or dispersed in a solvent to give a vanish forforming the adhesive layer, and the vanish is coated on the releasesubstrate 212, and after that, the solvent is removed by heating to formthe adhesive layer 214. Similarly, materials constituting the tackylayer 222 are dissolved or dispersed in a solvent to give a vanish forforming the tacky layer, and the vanish is coated on the substrate film224, and after that, the solvent is removed by heating to form the tackyfilm 220.

Here, the above-mentioned solvents used in the production of vanish arenot particularly limited, so long as they can solve or disperse variousconstituting materials. In view of the volatility upon formation oflayers, it is preferable to use solvents having a relatively low boilingpoint such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol,2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone,toluene, and xylene. In order to improve the coating property, solventshaving a relatively high boiling point such as dimethyl acetoamide,dimethylformamide, N-methylpyrrolidone, and cyclohexanone can be used.These solvents may be used alone or in combination thereof. It is alsopossible to remove bubbles from the vanish by vacuum exhausting afterproducing the vanish.

For coating the vanish on the release substrate 212 and substrate film224, known method may be used, and for example, a knife coating method,a roll coating method, a spray coating method, a gravure coating method,a bar coating method, a curtain coating method, and the like may beused.

Next, as mentioned above, the film in which the adhesive layer 214 isformed on the release substrate 212 (hereinafter referred to as“adhesive film”) and the tacky layer 222 is formed on the substrate film224 (hereinafter referred to as “tacky film 220”) are laminated, wherebythe adhesive sheet before precut (hereinafter referred to as a“precursor sheet” is formed to complete the first laminating step.

Here, the lamination of the adhesive film and the tacky film 220 may beperformed in a conventional known manner such as a method in which alaminator is used.

Also, the precursor sheet can be produced by the following method. Thatis, a method in which after the vanish for forming the adhesive layer iscoated on the release substrate 212, the solvent is removed by heatingto form the adhesive layer 214, on which the vanish for forming thetacky layer is coated, and then the solvent is removed by heating toform the tacky layer 222; a method in which after the vanish for formingthe tacky layer is coated on the substrate film 224, the solvent isremoved by heating to form the tacky layer 222, on which the vanish forforming the tacky layer is coated, and then the solvent is removed byheating to form the adhesive layer 214 may be employed.

In the first cutting step, the incision is made in the precursor sheetproduced as above from an opposite surface to the side bringing contactwith the tacky layer 222 of the substrate film 224 until the incisionreaches the release substrate 212, whereby the laminate 210 comprisingthe adhesive layer 12, the tacky layer 222, and the substrate film 224in a pre-determined plane shape and the incision D1 is formed in therelease substrate 212.

Here, the cutting of the laminate 210 can be performed using aprecutting blade C having a shape corresponding to the pre-determinedplane shape.

In the first cutting step, the incision is made so that the incisiondepth d1 of the incision D1 is less than the thickness of the releasesubstrate 212 and 25 μm or less. In order to obtain the adhesive sheet201 having better releasability, it is more preferable that the incisiondepth d1 of the incision D1 is 15 μm or less, still further preferably10 μm or less, particularly preferably 5 μm or less. As mentioned above,the closer to 0 μm the incision depth d1, the better the releasability,and the depth of more than 0 μm and 0.5 μm or less is the mostpreferable. However, form the viewpoint of the balance of the productionefficiency and the inhibition of peel defect, the incision depth d1 ispreferably from 5 to 15 μm.

Also, in the first cutting step, it is preferable that a value of (d1/a)satisfies a condition showing the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate 212.

This gives that the adhesive sheet 201 capable of sufficientlyinhibiting the peel defect can be obtained. In order to fully obtainsuch an effect, the upper limit of the value of (d1/a) in theabove-mentioned formula (2) is more preferably 0.5, still furtherpreferably 0.3, particularly preferably 0.25, extremely preferably 0.15,the most preferably 0.1.

After that, if necessary, an unnecessary part is peeled off and removedfrom the laminate 210 to obtain the adhesive sheet 201.

Eleventh Embodiment

A method for producing the adhesive sheet 202 concerning theabove-mentioned eighth embodiment in accordance with the eleventhembodiment will be described.

An adhesive sheet 202 is produced by a production method comprising asecond laminating step in which an adhesive layer 214 is laminated on arelease substrate 212; a second cutting step in which an incision ismade from an opposite surface to a side bringing contact with therelease substrate 212 of the adhesive layer 214, whereby the adhesivelayer 214 is cut in a pre-determined first plane shape and the firstincision D1 is formed in the release substrate 212; a third laminatingstep in which a tacky layer 222 and a substrate film 224 are laminatedin order so that, on the adhesive layer 214, the tacky layer 222 coversthe adhesive layer 214 and adheres to the release substrate 212 aroundthe adhesive layer 214; and a third cutting step in which an incision ismade from an opposite surface to the side bringing contact with thetacky layer 222 of the substrate film 224, whereby the substrate film224 and the tacky layer 222 are cut in pre-determined second planeshapes and the second incision D2 is formed in the release substrate212.

Here, in the second cutting step, the incision is made so that theincision depth d1 of the first incision D1 is less than the thickness ofthe release substrate 212 and 25 μm or less. In the third cutting step,the incision is made so that the incision depth d2 of the secondincision D2 is less than the thickness of the release substrate 212 and25 μm or less.

Now, each production step will be described in detail.

In the second laminating step, materials constituting the adhesive layer214 are dissolved or dispersed in a solvent to give a vanish for formingthe adhesive layer, and the vanish is coated on the release substrate212, and after that, the solvent is removed by heating to form theadhesive layer 214. By this operation, the adhesive sheet is formed andthe second laminating step is completed.

In the second cutting step, the incision is made in the adhesive filmproduced as above from the opposite surface to the side bringing contactwith the release substrate 212 of the adhesive layer 214 until theincision reaches the release substrate 212, whereby the adhesive layer214 is cut in a pre-determined first plane shape and the first incisionD1 is formed in the release substrate 212.

Here, the cutting of the laminate 214 can be performed using aprecutting blade C having a shape corresponding to the pre-determinedplane shape.

In the second cutting step, the incision is made so that the incisiondepth d1 of the incision D1 is less than the thickness of the releasesubstrate 212 and 25 μm or less. In order to obtain the adhesive sheet202 having better releasability, it is more preferable that the incisiondepth d1 of the incision D1 is 15 μm or less, still further preferably10 μm or less, particularly preferably 5 μm or less. As mentioned above,the closer to 0 μm the incision depth d1, the better the releasability,and the depth of more than 0 μm and 0.5 μm or less is the mostpreferable. However, form the viewpoint of the balance of the productionefficiency and the inhibition of peel defect, the incision depth d1 ispreferably from 5 to 15 μm.

Also, in the second cutting step, it is preferable that a value of(d1/a) satisfies a condition showing the following formula (2):0<(d1/a)≦0.7  (2)wherein a (μm) is a thickness of the release substrate 212.

This gives that the adhesive sheet 202 capable of sufficientlyinhibiting the peel defect can be obtained. In order to fully obtainsuch an effect, the upper limit of the value of (d1/a) in theabove-mentioned formula (2) is more preferably 0.5, still furtherpreferably 0.3, particularly preferably 0.25, extremely preferably 0.15,the most preferably 0.1.

After that, if necessary, an unnecessary part is peeled off and removedfrom the adhesive layer 214 to obtain the adhesive film.

In the third laminating step, the tacky layer 222 and the substrate film224 are laminated in order on the adhesive layer 214 which has beensubjected to the precut processing in the above-mentioned the secondcutting step so that the tacky layer 222 covers the adhesive layer andis brought contact with the release substrate 212 around the adhesivelayer 214 to produce the precursor sheet.

For laminating, for example, a method in which the tacky film 220comprising the tacky layer 222 is stuck to the substrate film 224 usinga laminator, or the like, a method in which a vanish for forming a tackylayer is coated on the adhesive layer 214, the solvent is removed byheating to form the tacky layer 222, on which the substrate film 224 isstuck, and the like may be employed.

In the third cutting step, the incision is made on the precursor sheetproduced above from the opposite surface to the side bringing contactwith the tacky layer 222 of the substrate film 224 until the incisionreach the release substrate 212, whereby the tacky film 220 comprisingthe substrate film 224 and the tacky layer 222 is cut in thepre-determined second plane shape and the second incision D2 is formedin the release substrate 212.

Here, the cutting of the tacky film 220 can be performed using aprecutting blade C having a shape corresponding to the pre-determinedplane shape.

In the third cutting step, the incision is made so that the incisiondepth d2 of the incision D2 is less than the thickness of the releasesubstrate 212 and 25 μm or less. In order to obtain the adhesive sheet202 having better releasability, it is more preferable that the incisiondepth d2 of the incision D2 is 15 μm or less, still further preferably10 μm or less, particularly preferably 5 μm or less. As mentioned above,the closer to 0 μm the incision depth d1, the better the releasability,and the depth of more than 0 μm and 0.5 μm or less is the mostpreferable. However, form the viewpoint of the balance of the productionefficiency and the inhibition of peel defect, the incision depth d2 ispreferably from 5 to 15 μm.

Also, in the third cutting step, it is preferable that a value of (d2/a)satisfies a condition showing the following formula (3):0<(d2/a)≦0.7  (3)wherein a (μm) is a thickness of the release substrate 212.

This gives that the adhesive sheet 202 capable of sufficientlyinhibiting the peel defect can be obtained. In order to fully obtainsuch an effect, the upper limit of the value of (d2/a) in theabove-mentioned formula (3) is more preferably 0.5, still furtherpreferably 0.3, particularly preferably 0.25, extremely preferably 0.15,the most preferably 0.1.

After that, if necessary, an unnecessary part is peeled off and removedfrom the adhesive layer 214 from the tacky film 220 to obtain theadhesive film 202.

Although the preferable embodiments of the adhesive sheet of the presentinvention and the method for producing the adhesive sheet were describedin detail as above, the present invention is not limited to theseembodiments. For example, the adhesive sheet 202 having the structureshown in FIG. 18 and FIG. 19 wherein the second incision D2 is notformed on the release substrate 212 may be used. The adhesive sheethaving such a structure can be produced, for example, by laminating theadhesive layer 214 on the release substrate 212, subjecting the adhesivelayer 214 to the precut processing, and sticking the tacky film 220which has previously been cut in a pre-determined plane shape so thatthe tacky layer 222 covers the adhesive layer 214 and is brought contactwith the release substrate 212 around the adhesive layer 214.

In the method for producing the adhesive sheet 202 concerning theeleventh embodiment, the third cutting step may not be performed. Inthis case, the adhesive sheet 203 in which the tacky film 220 is notsubjected to the precut processing, that is, having the structure shownin FIG. 20 and FIG. 21 can be obtained.

[Production Method of Semiconductor Device]

A method for producing a semiconductor device using the adhesive sheetdescribed above will be described using FIG. 22. In the followingdescription, a case in which as an adhesive sheet, the adhesive sheet202 in the above-mentioned eighth embodiment is used will be described.

FIG. 22 is a process chart showing series of steps for sticking alaminate 210 of an adhesive sheet 202 to a semiconductor wafer 32. Asshown in FIG. 22 (a), in the adhesive sheet 202, the release substrate212 serves as a carry film, and it is supported by two rolls 62 and 66,and a cuneate member 64. The adhesive sheet 202 is wound in a state inwhich its one end is attached to a cylindrical core 44 to form a firstroll 242, and its other end is attached to a cylindrical core 54 to forma second roll 252. To the core 54 of the second roll 252 is attached acore driving motor for rotating the core 54 (not shown in Fig.). Thisgives that after the laminate 210 is peeled off, the resulting releasesubstrate 210 is wound around the core 54 at a pre-determined speed.

First, when the core driving motor is rotated, the core 54 of the secondroll 252 is rotated, whereby the adhesive sheet 202 wound around thecore 44 of the first roll 242 is drawn outward from the first roll 242.The drawn adhesive sheet 202 is introduced on the disc-shapedsemiconductor wafer 32 placed on the mobile stage 36, and the wafer ring34 placed so as to surround the semiconductor wafer 32.

Next, the laminate 210 comprising the adhesive layer 214 and the tackyfilm 220 is peeled off from the release substrate 212. At this time, thecuneate member 64 is brought contact with the release substrate 212 fromthe release substrate 212 side of the adhesive sheet 202, whereby therelease substrate 212 is bent to the member 64 side at a sharp angle. Asa result, base points for peeling are formed between the releasesubstrate 212 and the laminate 210. Further, in order to moreefficiently form the base points for peeling, air is blown at a boundarysurface between the release substrate 212 and the laminate 210.

After the base points for peeling are formed between the releasesubstrate 212 and the laminate 210, as mentioned above, to which thelaminate 210 is stuck so that the tacky film 220 closely contacts thewafer ring 34 and the adhesive layer 214 closely contacts thesemiconductor wafer 32, as shown in FIG. 22 (b). At this time, thelaminate 210 is joined with pressure to the semiconductor wafer 32 byroll 68. After that, as shown in FIG. 22 (c), the lamination of thelaminate 210 on the semiconductor wafer 32 is completed to obtain thesemiconductor wafer having the laminate.

According to the above-mentioned procedure, the lamination of thelaminate 210 to the semiconductor wafer 32 can be continuously performedin an automatic step. Examples of the apparatus for laminating thelaminate 210 to the semiconductor wafer 32, used in the above-mentionedprocedure, may include, for example, RAD-2500™ manufactured by LintecCorporation, and the like.

When the laminate 210 is stuck to the semiconductor wafer 32 accordingto this step, the base points for peeling between the release substrate212 and the laminate 210 (the bases points for peeling between therelease substrate 212 and the tacky layer 222) can be easily formed byusing the adhesive sheet 202, and therefore the occurrence of the peeldefect can be fully inhibited.

Next, the semiconductor wafer having the laminate obtained in theabove-mentioned step is diced to give a semiconductor element with thelaminate having a necessary size. Further, in this process, steps fordrying or washing or the like may be performed. At this time, since thesemiconductor wafer 32 is sufficiently stuck and held to the laminate210 through the adhesive layer 214 and the tacky layer 222, falling ofthe semiconductor wafer is sufficiently inhibited during theabove-mentioned steps.

Next, high energy beams such as radial rays are irradiated to the tackylayer 222 of the laminate 210 to cure a part or a large part of thetacky layer 222 with polymerization. In this case, in order toaccelerate the curing reaction, the layer may be heated at the same timeof after the irradiation of the high energy beams.

The high energy beams are irradiated to the tacky layer 222 from asurface where the tacky layer 222 of the substrate film 224 is notformed. It is necessary that the substrate film 224 islight-transmissive, when ultraviolet ray is used as the high energybeams, accordingly. When electron beam is used as the high energy beams,the substrate film 224 is not necessary light-transmissive.

After the irradiation of the high energy beams, the semiconductorelement to be picked-up is picked-up with, for example, a suctioncollet. At this time, the semiconductor element to be picked-up can beknocked up with, for example, a needle rod from the under surface of thesubstrate film 224. By curing the tacky layer 222, the tack strengthbetween the semiconductor element and the adhesive layer 214 is greaterthan that between the adhesive layer 214 and the tacky layer 222, andtherefore, when the semiconductor element is picked-up, the peelingoccurs at an interface between the adhesive layer 214 and the tackylayer 222, and the semiconductor element having the adhesive layer inwhich the adhesive layer 214 adheres to the under surface of thesemiconductor element is picked-up.

This semiconductor element having the adhesive layer is mounted on asupport member for mounting a semiconductor element through the adhesivelayer 214, which is heated. The adhesive strength of the adhesive layer214 is expressed by heating, and the adhesion between the semiconductorelement and the support member for mounting a semiconductor element iscompleted.

After that, if necessary, a wire stick step and a sealing step areperformed to produce a semiconductor device.

[Semiconductor Device]

FIG. 23 is a schematic cross-section view showing one embodiment of asemiconductor element of the present invention, mentioned above.

As shown in FIG. 23, in the semiconductor device 300, two layers of thesemiconductor element having the adhesive layer comprising the adhesivelayer 214 and the semiconductor element 72 are laminated on the organicsubstrate 70, which is the support member for mounting a semiconductorelement. Also, the circuit pattern 74 and the terminal 76 are formed onthe organic substrate 70, and this circuit pattern 74 is attached to thetwo semiconductor elements 72 are through the wire stick 78, which issealed with the sealer 80 to form the semiconductor device 300. Thissemiconductor device 300 is produced using the adhesive sheet 202 inaccordance with the method for producing a semiconductor device of theabove-mentioned present invention.

Although the preferable embodiments of the method for producing thesemiconductor device of the present invention and the semiconductordevice were described in detail as above, the present invention is notlimited to these embodiments. For example, though the embodiment inwhich the adhesive sheet 202 is used in the method for producing asemiconductor device was described above, the adhesive sheet 201 or theadhesive sheet 203 may be used as the adhesive sheet. In case where theadhesive sheet 203 is used, after the laminate 210 in the adhesive sheet203 is stuck to the semiconductor wafer 32 and the wafer ring 34, thetacky film 220 in the laminate 210 is cut matching the diameter of thewafer ring 34. Examples of the apparatus for performing the operationmay include, for example, PM-8500™ manufactured by Nito SeikiManufacturing Corporation, and the like.

EXAMPLE

Now, the present invention will be described more specifically by meansof Examples and Comparative Examples, but the present invention is notlimited to the following Examples.

Synthesis Example 1 Synthesis of Acrylic Polymer

In a 500 ml four-necked separable flask equipped with a stirrer, adropping funnel, a thermometer, and a condenser was put 126.0 g of2-butanone, and the temperature of the flask was elevated to 80° C.while nitrogen gas was blown thereto at a flow rate of 100 ml/min, whichwas kept at that temperature for about 30 minutes. After that, while thetemperature was kept at 80° C., a solution in which 0.6 g of2,2-azobis(isobutyronitrile) was dissolved in a mixed liquid of 14.8 gof 2-butanone, 15.0 g of methacrylic acid, 15.0 g of methyl methacrylateand 70.0 g of 2-ethylhexyl acrylate was added dropwise to the 2-butanoneover 4 hours, and the mixture was kept at that time for 2 hours. Afterthat, a solution in which 0.06 g of 2,2-azobis(isobutyronitrile) wasdissolved in 8.5 g of 2-butanone was added dropwise to the mixture over30 minutes, which was kept at that temperature for 5.5 hours to give anacrylic polymer having a weight average molecular weight of 60,000 (avalue obtained by measuring with a gel permeation chromatography, andconverting with a standard polystyrene analytical curve) and anon-volatile component of 40% by mass.

Preparation Example 1 Production of Tacky Film

To a composition including 100 parts by mass of the acrylic polymersynthesized in Preparation Example 1, NK-ESTER BPE-200 (TM, manufacturedby Shin-Nakamura Chemical Co., Ltd), 22.05 parts by mass of2,2-bis(4-methacryloxyethoxyphenyl)propane, and 0.5 part by mass of1-hydroxycyclohexyl phenyl ketone was added 100 parts by mass of methylethyl ketone, which was stirred and degassed under vacuum to prepare avanish for forming a tacky layer. This vanish for forming a tacky layerwas coated on a 75 μm-thick polyethylene terephthalate (PET) film(manufactured by Teijin DuPont Film Limited, Teijin Purex S31), whichwas treated with a release agent, which was dried by heating at 100° C.for 5 minutes to form a tacky layer having a thickness of 10 μm. Thus,the pressure-sensitive adhesive film comprising the PET film and thetacky layer was obtained.

Example 1

First, to 60 parts by mass of YDCN-703 (TM, manufactured by Tohto KaseiCo., Ltd., cresol novolac type epoxy resin having an epoxy equivalentweight of 220) as an epoxy resin, and 40 parts by mass of XLC-LL (TM,manufactured by Mitsui Chemicals, Inc., phenol xylene glycol-dimethylether condensate) as a curing agent was added 1500 parts by mass ofcyclohexanone, and the mixture was stirred to prepare a first vanish.Then, to the first vanish were added 1 part by mass of NUC A-189 (TM,manufactured by Nippon Unicar Company Limited,γ-glycidoxypropyltrimethoxysilane) and 1 part by mass of NCU A-1160 (TM,manufactured by Nippon Unicar Company Limited,γ-ureidopropyltriethoxysilane) as coupling agents, to which R972V (TM,manufactured by Nihon Aerosil, a silica filler) was added in an amountof 10% by volume of the whole volume of the composition, and the mixturewas stirred, followed by dispersing treatment in a bead mill to preparea second vanish. To the second vanish were added 250 parts by mass ofHTR-860-P3 (TM, manufactured by Nagase Chemtex Corporation, an epoxygroup-containing acrylic copolymer) and 0.5 part by mass of Curezole2PZ-CN (TM, manufactured by Shikoku Chemicals Corporation,1-cyanoethyl-2-phenylimidazole) as a curing accelerator, and the mixturewas stirred to prepare a vanish for forming an adhesive layer.

This vanish for forming an adhesive layer was coated on a 38 μm-thickpolyethylene terephthalate (PET) film (manufactured by Teijin DuPontFilm Limited, Teijin Purex A31), which was treated with a release agent,which was dried at 140° C. for 5 minutes to form a 10 μm-thick adhesivelayer in B stage. Thus, the adhesive film comprising the PET film (therelease substrate) and the adhesive layer was obtained.

The obtained adhesive film was subjected to a circle precut processing(a first precut processing) to form an incision having an incision depthof 10 μm and φ210 mm in the release substrate.

After that, unnecessary parts were removed from the adhesive layer, thetacky layer of the tacky film was stuck to the adhesive layer at roomtemperature under conditions of a line pressure of 1 kg/cm and a rate of0.5 m/minute. The tacky film was subjected to a circle precut processing(a second precut processing) concentrically of the adhesive layer sothat an incision depth in the release substrate is 10 μm or less andφ290 mm to produce an adhesive sheet of Example 1.

When ten incision depths, which were arbitrarily selected, in therelease substrate in the first precut processing were measured, all ofthem were 10 μm or less, and the average value thereof (d1) was 8 μm.Similarly, when ten incision depths, which were arbitrarily selected, inthe release substrate in the second precut processing were measured, allof them were 10 μm or less, and the average value thereof (d2) was 9 μm.The measurement of these incision depths was performed by cross-sectionobservation with an electron microscope.

Example 2

An adhesive sheet of Example 2 was produced in the same manner as inExample 1 except that the first and second precut processing wereperformed so that the incision depths in the release substrate is 20 μmor less.

When ten incision depths, which were arbitrarily selected, in therelease substrate in the first precut processing were measured, all ofthem were 20 μm or less, and the average value thereof (d1) was 15 μm.Similarly, when ten incision depths, which were arbitrarily selected, inthe release substrate in the second precut processing were measured, allof them were 20 μm or less, and the average value thereof (d2) was 16μm.

Comparative Example 1

An adhesive sheet of Comparative Example 1 was produced in the samemanner as in Example 1 except that the first and second precutprocessing were performed so that the incision depths in the releasesubstrate is 35 μm or less.

When ten incision depths, which were arbitrarily selected, in therelease substrate in the first precut processing were measured, all ofthem were within a range of 25 to 35 μm, and the average value thereof(d1) was 31 μm. Similarly, when ten incision depths, which werearbitrarily selected, in the release substrate in the second precutprocessing were measured, all of them were within a range of 25 to 35μm, and the average value thereof (d2) was 30 μm.

(Evaluation of Peel Defect)

The laminates comprising the adhesive layer and the tacky film waspeeled off from the release substrates in the adhesive sheets obtainedin Examples 1 and 2, and Comparative Example 1, and the peel defect wasevaluated as follows: First, 100 adhesive sheets (an adhesive sheet inwhich 100 laminates comprising the tacky film and the adhesive layer onone release substrate) were prepared for each of Examples 1 and 2, andComparative Example 1. Then, a laminating test to a wafer was performedusing a wafer mounting apparatus (RAD-2500) manufactured by LintecCorporation. In this test, the wafer size was φ8 inches (203 mm), thethickness was 150 μm, and the laminating rate was 35 mm/second. When thelaminate was not peeled off from the release substrate and was not stuckto the wafer, such a film was evaluated as peel defect, and the numberof the peel defect to the number of tests, 100. The results are shown inTable 1.

TABLE 1 The number of the peel defect Example 1 0 Example 2 0Comparative Example 1 27

As apparent from the results of Table 1, it was confirmed that theadhesive sheets of Examples 1 and 2 could more sufficiently be inhibitedfrom the peel defect than the adhesive sheet of Comparative Example 1.

What is claimed is:
 1. A method for producing a semiconductor device,comprising: peeling off a laminate, including an adhesive layer, a tackylayer and a substrate film in an adhesive sheet from a release substrateof the adhesive sheet, the adhesive sheet comprising the releasesubstrate, the adhesive layer, the tacky layer, and the substrate film,laminated in order, and sticking the laminate through the adhesive layerto a semiconductor wafer to give a semiconductor wafer having thelaminate; dicing the semiconductor wafer having the laminate to give asemiconductor element having a laminate with a pre-determined size;irradiating the tacky layer with high energy beams to lower the tackstrength of the tacky layer to the adhesive layer, and then peeling thetacky layer and the substrate film from the adhesive layer to give asemiconductor element having the adhesive layer; and bonding thesemiconductor element having the adhesive layer through the adhesivelayer to a support member for mounting a semiconductor element, whereinthe adhesive layer has a pre-determined first plane shape and is formedon part of the release substrate; wherein a first incision is formed inthe release substrate from a side bringing contact with the adhesivelayer along the periphery of the plane shape of the adhesive layer;wherein the release substrate has a thickness of 30-50 μm; and whereinthe first incision has a depth of greater than zero, and less than 25μm.
 2. The method for producing a semiconductor device according toclaim 1, wherein the tacky layer and the substrate film are peeled fromthe adhesive layer by picking up the semiconductor element having theadhesive layer from the tacky layer.
 3. The method for producing asemiconductor device according to claim 1, wherein the incision has adepth in the range of 5-15 μm.